CA1226929A - Multiple wavelength light emitting devices - Google Patents
Multiple wavelength light emitting devicesInfo
- Publication number
- CA1226929A CA1226929A CA000492495A CA492495A CA1226929A CA 1226929 A CA1226929 A CA 1226929A CA 000492495 A CA000492495 A CA 000492495A CA 492495 A CA492495 A CA 492495A CA 1226929 A CA1226929 A CA 1226929A
- Authority
- CA
- Canada
- Prior art keywords
- light emitting
- multiwavelength
- regions
- devices
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/0004—Devices characterised by their operation
- H01L33/0008—Devices characterised by their operation having p-n or hi-lo junctions
- H01L33/0016—Devices characterised by their operation having p-n or hi-lo junctions having at least two p-n junctions
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
- G02B6/4228—Passive alignment, i.e. without a detection of the degree of coupling or the position of the elements
- G02B6/423—Passive alignment, i.e. without a detection of the degree of coupling or the position of the elements using guiding surfaces for the alignment
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4249—Packages, e.g. shape, construction, internal or external details comprising arrays of active devices and fibres
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
- H01L25/03—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes
- H01L25/04—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers
- H01L25/075—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L33/00
- H01L25/0756—Stacked arrangements of devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components with at least one potential-jump barrier or surface barrier specially adapted for light emission
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/0001—Technical content checked by a classifier
- H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
Abstract
ABSTRACT
MULTIPLE WAVELENGTH LIGHT EMITTING DEVICES
Presented is a dual wavelength structure wherein two edge-emitting devices (10,11) are bonded with p-regions (12,13) adjacent. The bonding medium (102) is a conductive material that forms a common electrode between the devices. Each device is separately addressable. Efficient coupling of emitted light into a single fiber (123) is accomplished by restricting the vertical and horizontal separation of the light emitting stripes (16,17).
MULTIPLE WAVELENGTH LIGHT EMITTING DEVICES
Presented is a dual wavelength structure wherein two edge-emitting devices (10,11) are bonded with p-regions (12,13) adjacent. The bonding medium (102) is a conductive material that forms a common electrode between the devices. Each device is separately addressable. Efficient coupling of emitted light into a single fiber (123) is accomplished by restricting the vertical and horizontal separation of the light emitting stripes (16,17).
Description
I
, I. CAM LIBEL 15-10-3 MULTIPLE WAVELENGTH LIGHT EMITTING DEVICES
Background of the Invention This invention relates to light emitting devices for use primarily in light wave transmission systems.
The very wide transmission window from about 0.8 to 1.6 us in present low-loss optical fibers permits the use of wavelength multiplexing to increase the transmission capacity of a -fiber.
Multiple wavelength light emitting devices which operate in this range have previously been disclosed. See, for example, the article entitled "Dual-Wavelength Surface Emitting InGaAsP Leeds" by TOP.
Lee, KIWI. Burrs and AGO. Denial, Electronics Letters, 16, page 845 (1980) or the article entitled "A Transparent InGaAsP-InP
Luminescent Diode for Optical Wavelength Multiplex Operation of Fiber Systems," by WOE. Proebster and H. Growth, IEEE Transactions Electron Devices ED-30, page 119 (1983).
, The prior art devices are generally monolithic structures.
Producing a second wavelength in a monolithic structure usually requires growing two active layers with different band gaps either in a single growth procedure or a consecutive growth procedure with an intermediate etch step. The former procedure involves complex processing to electrically access the active layers individually while the latter involves a difficult regrowth process.
It has been proposed to provide a multi wavelength light emitting device by using individual Lids emitting a different wavelengths and coupling them in series using short lengths of optical fiber. (See Proebsker and Growth, "A Transparent InGaAsP-InP Luminescent Diode...," IEEE Transactions Electron Devices ED-30, page 119 (1983).) Lyle this approach has many advantages, it may also involve costly, complex, ~lltiple LED to fixer alignments.
5_ With the invention as claimed the light omitting regions are close enough to be coupled to a common optical fire, but since the light emitting devices are distinct devices, bonded together, as opposed to parts of a single monolithic structure, it is a I
comparatively simple matter to address the devices separately and to suppress interaction between the devices.
In accordance with an aspect of the invention there is provided a multi wavelength light emitting device comprising: two light emitting devices, each comprising a confined light emitting region which emits light at a different wavelength, said devices being bonded with a conductive material that forms a common electrode between them, the light emitting regions being sufficiently close together to couple light from both regions into a sigrlle optical fiber; and means for electrically addressing each device separately.
Brief Description ox the Drawn An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-FIG. 1 is a perspective, partly schematic, view of a device in accordance with one embodiment of the invention; and FIG. 2-5 are cross sectional views in more detail of the device of FIG. L during various stages of fabrication.
It will be appreciated that for purposes of illustration these Figures are not drawn to scale.
llet~iled Orate _ Presented in FIG. 1 is an embodiment ox a dull wavelength light emitting device in accordance with the invention.
The structure includes two light emitting devices 10 and 11~ which are hounded together 50 that there is a common conductive layer 102 between them. One device 10 is shorter than the other 11 to allow electrical access to the common electrode 102 through an ohmic contact layer on the surface of the bottom device this layer is not shown in JIG. 1 for the sake of clarity in the illustration but - pa -is presented in FIG. 5 as layer 131). Typically, the top device 10 is approximately 200 em long while the bottom device 11 is approximately 400 em long. Ohmic contact layers 101 and 103 are formed on the opposite surfaces ox each device. Pulse sources 18 and 19 are connected between electrodes 101 and 102 and electrodes 103 and 102 respectively, so that each device is forward biased individually and the devices can be operated independently.
Each device 10 and 11 is an edge emitting light emitting diode LYDIA which includes at least one p-region 12 and 13 and one n-region 14 and 15. The confined light emitting regions are illustrated schematically in FIG. 1 as the dots 16 and 17 located at the p-n junction of each device. As also illustrated 7 the individual devices are constructed and bonded so that the light emitting regions are sufficiently close together to permit coupling the light from both regions into a single optical fiber 123.
I>
. .
to In general, each device 10 and 11 is identical except that tune active regions are of different material compositions to emit at different wavelengths. It is also generally desirable to fabricate thin p-regions and bond the two devices so that their p-regions are adjacent in order to couple the light efficiently into the fiber.
FIG. 5 illustrates the dual wavelength light emitting structure in more detail while FIGS. 2-4 show the fabrication of the individual devices For inclusion in the final structure. us shown in FIG. 2 each device consists of -four epitaxial layers 106, 108, 110, 112 for device 11 and 109, 111, 113, 115 for device 10 grown by liquid phase epitaxy on a ~100~ oriented Snooped n-type In substrate 114 and 117 with an impurity concentration of 5 x 101~cm~3. Layer compositions are as follows:
an n-type, em thick, Snooped In buffer layer with an impurity concentration of 1 x 1018cm~3 112 and 115;
an n-type, 0.2 us thick Snooped InGaAsP active layer with an impurity concentration of 1 x lOl~cm-3 110 and 113;
a p-type, em thick Zn-doped In confining layer with an impurity concentration of S x 1017cm~3 108 and 111; and an n-type, em thick, Snooped In layer with an impurity concentration of 5 x 1018cm~3 106 and 109.
To form the light emitting stripes 124 and 125 of FIG. 5, a 3 em wide V-groove 105 and 130 is etched into the device surfaces as shown in FIG. 3. The Y-groove is formed by etching the cap layer 106 and 109 through a photo resist mask with stripe-shaped openings oriented along the ~110 7 direction.
As shown on FIG. 4, after formation of the epitaxlal layers 106 and 109 and the grooves 105 and 130~ the devices are subjected to a Zen diffusion process to transform part of layers 106 and 109 into p-type layers 104 and 107.
The remaining n-type regions of layers 106 and 109 (84, 94 and 87, 97) serve to restrict current flow -from layer 104 to layer 108 in device 11 and from layer 107 to layer 111 in device 10, in order to confine the region of fight emission from layers 110 and 113 to the regions 125 and 124. Owl no to the presence of the grooves, a so part of the D-region Jill extend completely through fevers 106 and 109 to give the strllcture shown and electrically define the area of the stripes. The dashed lines indicate the extent of Zen diffusion.
This type of light emitting device structure is shown in US. Patent 4,278,949 issued to P. Marshall.
After each device has been thinned to 100 my the D-surfaces are metallized with Beau layers 131 and 132 and the n surfaces are metallized with Assign layers 101 and 103, which layers are typically 0.08 em thick and 0.5 elm thick, respectively. Lastly, gold heat sinks 120 and 121 are electroplated onto the top surface of each device typically to a thickness of approximately 2.0 em.
Conveniently, each device can be formed from separate single wafers and then cleaved apart.
In this example, the two devices were identical except for the active layers 110 and 113, where the composition was varied to cause different wavelengths of light emission. The composition of layer 110 was typically Ion g3Gao.17A50.64P0.36 so that the wavelength of the peak emission was approximately 1.1 em while the composition of layer 113 was typically Ino.70Gao.30As0.64Po.36 so that the wavelength of the peak emission was approximately 1.3 em.
As shown in FIG. 5, the two devices are bonded p-surface to p-surface by means of a conductive layer 102 fur example a silver filled epoxy such as that sold by Able bond under the designation "36-2 silver filled epoxy". The spacing between the light emitting stripes 124 and 125 is minimized in the vertical direction in order to couple the emitted light efficiently into an optical fiber. The vertical spacing bottle the light emitting regions is dependent upon the thickness of the epoxy lo 2 em), the combined thickness ox the two heat sinks and Beau contact layers By 4 Jim), the thickness of the active layers 113 and 110, confining layers 111 and 108, the pinup, and the last ogre nip layer for both Lids (PA
10 em). Since the core diameter of commonly used transmission -fibers is less than 85 my the maximum vertical separation of the light emitting stripes should be 25 lam. The vertical separation of I
the present structure is 14-16 em but can be reduced to approximately 13 em by reducing the thickness of the epitaxial layers and heat sinks. The vertical separation parameter is dependent upon the system one intends to use and the core diameter of the optical fiber used. In general, the vertical separation of the light emitting stripes in the dual wavelength device presented may be enlarged to 100 em to simplify device fabrication or reduced to a minimum of 5 em to increase coupled power, depending upon desired use.
Horizontal alignment is achieved in one dimension by making the front surfaces of the device (facing the fixer) as slush as possible. In the other dimension, alignment within 20 em can be achieved by fabricating each light emitting stripe with its center within 10 em of the center of the device chip and then centering the top device over the bottom device. The formation of the 'I-grooves 105 and 130 aids in the horizontal alignment since a slight dimple will be formed in the overlying metal thereby identifying the position of the stripe A recommended maximum horizontal tolerance for the fiber employed is 25 em.
The fiber 123 (FIG. 1) used in this embodiment had a 6~.5 em core and a numerical aperture (NAY of 0.29. To improve the coupling efficiency, a 125 elm diameter lens 122 is glued to the end ox the giber. Tests on several devices Yielded data on launched power and light output as a function of bias current. The maximum launched power at 50 ma bias was 52 for I = 1.3 em and 30 OW for I =
1.1 em.
The values of the launched power of the described structure are in good agreement with accepted system loss and desired results.
Where is also approximately a linear relation between the light output and current from within the range 5 Moe ma Within this range, the temperature dependence ox the light output is expected to be comparable to that of surface emitting Lids, i.e., To = 180K
(surface) and To = 110K (edge emitting) where To is a characteristic temperature to what Particular device. the temperature dependence of the launched power is empirically proportional to exit jury T = temperature and To =
characteristic temperature). Since our dual wavelength structure is composed of two individual edge-emitters laid one on top of the other with intervening metallization, (i.e. gold heat sinks 120 and 121 and Beau layers 131 and 132 as well as conductive layer 102), spectral problems due to the optical interaction of the two devices do not occur. That is, problems itch might have arisen because of photo-excitation of one device by another are corrected in part by the intervening metallization acting as a shield against interaction of the two devices.
In the experimental devices the coupling efficiency decreased at most by 3.6 dub when the fiber was repositioned so as to couple the light from both sources, as compared to coupling from a single source.
It should be understood that the invention presented here is not limited to this Particular embodiment. Any edge-emitting laser or light emitting diode may be employed in the present structure provided the distance between light emitting areas falls within the constraints previously mentioned. For example, the devices could have a greater or lesser number of layers than shown in FIG. 2, and any manner of stripe geometry formation may be employed.
Further, the two devices employed in the structure need not be identical, buy could have completely different geometries and/or material compositions.
, I. CAM LIBEL 15-10-3 MULTIPLE WAVELENGTH LIGHT EMITTING DEVICES
Background of the Invention This invention relates to light emitting devices for use primarily in light wave transmission systems.
The very wide transmission window from about 0.8 to 1.6 us in present low-loss optical fibers permits the use of wavelength multiplexing to increase the transmission capacity of a -fiber.
Multiple wavelength light emitting devices which operate in this range have previously been disclosed. See, for example, the article entitled "Dual-Wavelength Surface Emitting InGaAsP Leeds" by TOP.
Lee, KIWI. Burrs and AGO. Denial, Electronics Letters, 16, page 845 (1980) or the article entitled "A Transparent InGaAsP-InP
Luminescent Diode for Optical Wavelength Multiplex Operation of Fiber Systems," by WOE. Proebster and H. Growth, IEEE Transactions Electron Devices ED-30, page 119 (1983).
, The prior art devices are generally monolithic structures.
Producing a second wavelength in a monolithic structure usually requires growing two active layers with different band gaps either in a single growth procedure or a consecutive growth procedure with an intermediate etch step. The former procedure involves complex processing to electrically access the active layers individually while the latter involves a difficult regrowth process.
It has been proposed to provide a multi wavelength light emitting device by using individual Lids emitting a different wavelengths and coupling them in series using short lengths of optical fiber. (See Proebsker and Growth, "A Transparent InGaAsP-InP Luminescent Diode...," IEEE Transactions Electron Devices ED-30, page 119 (1983).) Lyle this approach has many advantages, it may also involve costly, complex, ~lltiple LED to fixer alignments.
5_ With the invention as claimed the light omitting regions are close enough to be coupled to a common optical fire, but since the light emitting devices are distinct devices, bonded together, as opposed to parts of a single monolithic structure, it is a I
comparatively simple matter to address the devices separately and to suppress interaction between the devices.
In accordance with an aspect of the invention there is provided a multi wavelength light emitting device comprising: two light emitting devices, each comprising a confined light emitting region which emits light at a different wavelength, said devices being bonded with a conductive material that forms a common electrode between them, the light emitting regions being sufficiently close together to couple light from both regions into a sigrlle optical fiber; and means for electrically addressing each device separately.
Brief Description ox the Drawn An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:-FIG. 1 is a perspective, partly schematic, view of a device in accordance with one embodiment of the invention; and FIG. 2-5 are cross sectional views in more detail of the device of FIG. L during various stages of fabrication.
It will be appreciated that for purposes of illustration these Figures are not drawn to scale.
llet~iled Orate _ Presented in FIG. 1 is an embodiment ox a dull wavelength light emitting device in accordance with the invention.
The structure includes two light emitting devices 10 and 11~ which are hounded together 50 that there is a common conductive layer 102 between them. One device 10 is shorter than the other 11 to allow electrical access to the common electrode 102 through an ohmic contact layer on the surface of the bottom device this layer is not shown in JIG. 1 for the sake of clarity in the illustration but - pa -is presented in FIG. 5 as layer 131). Typically, the top device 10 is approximately 200 em long while the bottom device 11 is approximately 400 em long. Ohmic contact layers 101 and 103 are formed on the opposite surfaces ox each device. Pulse sources 18 and 19 are connected between electrodes 101 and 102 and electrodes 103 and 102 respectively, so that each device is forward biased individually and the devices can be operated independently.
Each device 10 and 11 is an edge emitting light emitting diode LYDIA which includes at least one p-region 12 and 13 and one n-region 14 and 15. The confined light emitting regions are illustrated schematically in FIG. 1 as the dots 16 and 17 located at the p-n junction of each device. As also illustrated 7 the individual devices are constructed and bonded so that the light emitting regions are sufficiently close together to permit coupling the light from both regions into a single optical fiber 123.
I>
. .
to In general, each device 10 and 11 is identical except that tune active regions are of different material compositions to emit at different wavelengths. It is also generally desirable to fabricate thin p-regions and bond the two devices so that their p-regions are adjacent in order to couple the light efficiently into the fiber.
FIG. 5 illustrates the dual wavelength light emitting structure in more detail while FIGS. 2-4 show the fabrication of the individual devices For inclusion in the final structure. us shown in FIG. 2 each device consists of -four epitaxial layers 106, 108, 110, 112 for device 11 and 109, 111, 113, 115 for device 10 grown by liquid phase epitaxy on a ~100~ oriented Snooped n-type In substrate 114 and 117 with an impurity concentration of 5 x 101~cm~3. Layer compositions are as follows:
an n-type, em thick, Snooped In buffer layer with an impurity concentration of 1 x 1018cm~3 112 and 115;
an n-type, 0.2 us thick Snooped InGaAsP active layer with an impurity concentration of 1 x lOl~cm-3 110 and 113;
a p-type, em thick Zn-doped In confining layer with an impurity concentration of S x 1017cm~3 108 and 111; and an n-type, em thick, Snooped In layer with an impurity concentration of 5 x 1018cm~3 106 and 109.
To form the light emitting stripes 124 and 125 of FIG. 5, a 3 em wide V-groove 105 and 130 is etched into the device surfaces as shown in FIG. 3. The Y-groove is formed by etching the cap layer 106 and 109 through a photo resist mask with stripe-shaped openings oriented along the ~110 7 direction.
As shown on FIG. 4, after formation of the epitaxlal layers 106 and 109 and the grooves 105 and 130~ the devices are subjected to a Zen diffusion process to transform part of layers 106 and 109 into p-type layers 104 and 107.
The remaining n-type regions of layers 106 and 109 (84, 94 and 87, 97) serve to restrict current flow -from layer 104 to layer 108 in device 11 and from layer 107 to layer 111 in device 10, in order to confine the region of fight emission from layers 110 and 113 to the regions 125 and 124. Owl no to the presence of the grooves, a so part of the D-region Jill extend completely through fevers 106 and 109 to give the strllcture shown and electrically define the area of the stripes. The dashed lines indicate the extent of Zen diffusion.
This type of light emitting device structure is shown in US. Patent 4,278,949 issued to P. Marshall.
After each device has been thinned to 100 my the D-surfaces are metallized with Beau layers 131 and 132 and the n surfaces are metallized with Assign layers 101 and 103, which layers are typically 0.08 em thick and 0.5 elm thick, respectively. Lastly, gold heat sinks 120 and 121 are electroplated onto the top surface of each device typically to a thickness of approximately 2.0 em.
Conveniently, each device can be formed from separate single wafers and then cleaved apart.
In this example, the two devices were identical except for the active layers 110 and 113, where the composition was varied to cause different wavelengths of light emission. The composition of layer 110 was typically Ion g3Gao.17A50.64P0.36 so that the wavelength of the peak emission was approximately 1.1 em while the composition of layer 113 was typically Ino.70Gao.30As0.64Po.36 so that the wavelength of the peak emission was approximately 1.3 em.
As shown in FIG. 5, the two devices are bonded p-surface to p-surface by means of a conductive layer 102 fur example a silver filled epoxy such as that sold by Able bond under the designation "36-2 silver filled epoxy". The spacing between the light emitting stripes 124 and 125 is minimized in the vertical direction in order to couple the emitted light efficiently into an optical fiber. The vertical spacing bottle the light emitting regions is dependent upon the thickness of the epoxy lo 2 em), the combined thickness ox the two heat sinks and Beau contact layers By 4 Jim), the thickness of the active layers 113 and 110, confining layers 111 and 108, the pinup, and the last ogre nip layer for both Lids (PA
10 em). Since the core diameter of commonly used transmission -fibers is less than 85 my the maximum vertical separation of the light emitting stripes should be 25 lam. The vertical separation of I
the present structure is 14-16 em but can be reduced to approximately 13 em by reducing the thickness of the epitaxial layers and heat sinks. The vertical separation parameter is dependent upon the system one intends to use and the core diameter of the optical fiber used. In general, the vertical separation of the light emitting stripes in the dual wavelength device presented may be enlarged to 100 em to simplify device fabrication or reduced to a minimum of 5 em to increase coupled power, depending upon desired use.
Horizontal alignment is achieved in one dimension by making the front surfaces of the device (facing the fixer) as slush as possible. In the other dimension, alignment within 20 em can be achieved by fabricating each light emitting stripe with its center within 10 em of the center of the device chip and then centering the top device over the bottom device. The formation of the 'I-grooves 105 and 130 aids in the horizontal alignment since a slight dimple will be formed in the overlying metal thereby identifying the position of the stripe A recommended maximum horizontal tolerance for the fiber employed is 25 em.
The fiber 123 (FIG. 1) used in this embodiment had a 6~.5 em core and a numerical aperture (NAY of 0.29. To improve the coupling efficiency, a 125 elm diameter lens 122 is glued to the end ox the giber. Tests on several devices Yielded data on launched power and light output as a function of bias current. The maximum launched power at 50 ma bias was 52 for I = 1.3 em and 30 OW for I =
1.1 em.
The values of the launched power of the described structure are in good agreement with accepted system loss and desired results.
Where is also approximately a linear relation between the light output and current from within the range 5 Moe ma Within this range, the temperature dependence ox the light output is expected to be comparable to that of surface emitting Lids, i.e., To = 180K
(surface) and To = 110K (edge emitting) where To is a characteristic temperature to what Particular device. the temperature dependence of the launched power is empirically proportional to exit jury T = temperature and To =
characteristic temperature). Since our dual wavelength structure is composed of two individual edge-emitters laid one on top of the other with intervening metallization, (i.e. gold heat sinks 120 and 121 and Beau layers 131 and 132 as well as conductive layer 102), spectral problems due to the optical interaction of the two devices do not occur. That is, problems itch might have arisen because of photo-excitation of one device by another are corrected in part by the intervening metallization acting as a shield against interaction of the two devices.
In the experimental devices the coupling efficiency decreased at most by 3.6 dub when the fiber was repositioned so as to couple the light from both sources, as compared to coupling from a single source.
It should be understood that the invention presented here is not limited to this Particular embodiment. Any edge-emitting laser or light emitting diode may be employed in the present structure provided the distance between light emitting areas falls within the constraints previously mentioned. For example, the devices could have a greater or lesser number of layers than shown in FIG. 2, and any manner of stripe geometry formation may be employed.
Further, the two devices employed in the structure need not be identical, buy could have completely different geometries and/or material compositions.
Claims (9)
1. A multiwavelength light emitting device comprising:
two light emitting devices, each comprising a confined light emitting region which emits light at a different wavelength, said devices being bonded with a conductive material that forms a common electrode between them, the light emitting regions being sufficiently close together to couple light from both regions into a single optical fiber; and means for electrically addressing each device separately.
two light emitting devices, each comprising a confined light emitting region which emits light at a different wavelength, said devices being bonded with a conductive material that forms a common electrode between them, the light emitting regions being sufficiently close together to couple light from both regions into a single optical fiber; and means for electrically addressing each device separately.
2. The multiwavelength device according to claim 1 further comprising a heat sink between each light emitting device and the common electrode.
3. The multiwavelength device according to claim 1 wherein the vertical separation of the light emitting regions lies within the range of 5 µm to 100 µm.
4. The multiwavelength device according to claim 1 wherein the vertical separation of the light emitting regions is no greater than 25 µm.
5. The multiwavelength device according to claim 1 wherein the means for electrically addressing each light emitting device comprises ohmic contact layers formed on the surfaces of the light emitting devices opposite the bonded surfaces.
6. The multiwavelength device according to claim 1 wherein the length of one light emitting device is greater than the length of the other light emitting device, in order to permit electrical access to the common electrode.
7. The multiwavelength device according to claim 2 wherein the heat sink serves also as a shield against photo-excitation of one device by the other.
8. The multiwavelength device according to claim 1 wherein each device includes an n-type region and a p-type region, and the devices are bonded so that their p-type regions are in close proximity without any intervening n-type region.
9. The multiwavelength device according to claim 1 further comprising an optical fiber which is aligned with said light emitting regions so that light from both regions is coupled into said fiber.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/658,568 US4605942A (en) | 1984-10-09 | 1984-10-09 | Multiple wavelength light emitting devices |
| US658,568 | 1984-10-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1226929A true CA1226929A (en) | 1987-09-15 |
Family
ID=24641782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000492495A Expired CA1226929A (en) | 1984-10-09 | 1985-10-08 | Multiple wavelength light emitting devices |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4605942A (en) |
| EP (1) | EP0197117B1 (en) |
| JP (1) | JPS62500415A (en) |
| CA (1) | CA1226929A (en) |
| DE (1) | DE3569635D1 (en) |
| WO (1) | WO1986002491A1 (en) |
Families Citing this family (38)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0728022B2 (en) * | 1985-05-07 | 1995-03-29 | 株式会社日立製作所 | Electronic device with optical signal transmission system |
| US4725128A (en) * | 1985-11-20 | 1988-02-16 | Medtronic, Inc. | Method for delivering light from multiple light emitting diodes over a single optical fiber |
| US4787086A (en) * | 1986-05-19 | 1988-11-22 | American Telephone And Telegraph Company, At&T Bell Laboratories | High-power, fundamental transverse mode laser |
| JPS6395682A (en) * | 1986-10-09 | 1988-04-26 | Mitsubishi Electric Corp | End-surface light-emitting device |
| FR2605801B1 (en) * | 1986-10-23 | 1989-03-03 | Menigaux Louis | METHOD FOR MANUFACTURING A SEMICONDUCTOR STRUCTURE CAPABLE OF MULTI-WAVELENGTH LENGTH, AND DEVICE OBTAINED |
| DE3925201A1 (en) * | 1989-07-29 | 1991-02-07 | Messerschmitt Boelkow Blohm | OPTICAL BENCH FOR MOUNTING OPTICAL, ELECTRICAL AND OTHERS COMPONENTS |
| EP0420695B1 (en) * | 1989-09-29 | 1994-11-17 | Shin-Etsu Handotai Company Limited | Multiple wavelength light emitting device |
| US5307357A (en) * | 1992-11-05 | 1994-04-26 | International Business Machines Corporation | Protection means for ridge waveguide laser structures using thick organic films |
| US5305340A (en) * | 1992-12-16 | 1994-04-19 | International Business Machines Corporation | Waveguide ridge laser device with improved mounting and ridge protection |
| JPH07115244A (en) * | 1993-10-19 | 1995-05-02 | Toyota Motor Corp | Semiconductor laser and its fabrication |
| US6548956B2 (en) | 1994-12-13 | 2003-04-15 | The Trustees Of Princeton University | Transparent contacts for organic devices |
| US6358631B1 (en) | 1994-12-13 | 2002-03-19 | The Trustees Of Princeton University | Mixed vapor deposited films for electroluminescent devices |
| US5703436A (en) * | 1994-12-13 | 1997-12-30 | The Trustees Of Princeton University | Transparent contacts for organic devices |
| US5707745A (en) | 1994-12-13 | 1998-01-13 | The Trustees Of Princeton University | Multicolor organic light emitting devices |
| US6633120B2 (en) | 1998-11-19 | 2003-10-14 | Unisplay S.A. | LED lamps |
| GB2366074A (en) * | 2000-02-15 | 2002-02-27 | Hassan Paddy Abdel Salam | LED light source with two vertically-stacked LEDs of different colours |
| US5960024A (en) | 1998-03-30 | 1999-09-28 | Bandwidth Unlimited, Inc. | Vertical optical cavities produced with selective area epitaxy |
| US5991326A (en) | 1998-04-14 | 1999-11-23 | Bandwidth9, Inc. | Lattice-relaxed verticle optical cavities |
| US6493372B1 (en) | 1998-04-14 | 2002-12-10 | Bandwidth 9, Inc. | Vertical cavity apparatus with tunnel junction |
| US6487230B1 (en) | 1998-04-14 | 2002-11-26 | Bandwidth 9, Inc | Vertical cavity apparatus with tunnel junction |
| US6493373B1 (en) | 1998-04-14 | 2002-12-10 | Bandwidth 9, Inc. | Vertical cavity apparatus with tunnel junction |
| US6487231B1 (en) | 1998-04-14 | 2002-11-26 | Bandwidth 9, Inc. | Vertical cavity apparatus with tunnel junction |
| US6535541B1 (en) | 1998-04-14 | 2003-03-18 | Bandwidth 9, Inc | Vertical cavity apparatus with tunnel junction |
| US6493371B1 (en) | 1998-04-14 | 2002-12-10 | Bandwidth9, Inc. | Vertical cavity apparatus with tunnel junction |
| US6760357B1 (en) | 1998-04-14 | 2004-07-06 | Bandwidth9 | Vertical cavity apparatus with tunnel junction |
| US6365968B1 (en) | 1998-08-07 | 2002-04-02 | Corning Lasertron, Inc. | Polyimide/silicon oxide bi-layer for bond pad parasitic capacitance control in semiconductor electro-optical device |
| US6226425B1 (en) | 1999-02-24 | 2001-05-01 | Bandwidth9 | Flexible optical multiplexer |
| US6275513B1 (en) | 1999-06-04 | 2001-08-14 | Bandwidth 9 | Hermetically sealed semiconductor laser device |
| US6233263B1 (en) | 1999-06-04 | 2001-05-15 | Bandwidth9 | Monitoring and control assembly for wavelength stabilized optical system |
| JP4038375B2 (en) * | 1999-08-04 | 2008-01-23 | 株式会社日立製作所 | Laser module, optical head using the same, and optical information recording / reproducing apparatus |
| US7439551B2 (en) * | 2004-07-08 | 2008-10-21 | Sharp Kabushiki Kaisha | Nitride-based compound semiconductor light emitting device |
| JP4371956B2 (en) | 2004-09-02 | 2009-11-25 | シャープ株式会社 | Nitride-based compound semiconductor light-emitting device and method for manufacturing the same |
| JP4767035B2 (en) * | 2005-04-12 | 2011-09-07 | シャープ株式会社 | Nitride-based semiconductor light-emitting device and manufacturing method thereof |
| US20070029555A1 (en) * | 2005-08-04 | 2007-02-08 | Lester Steven D | Edge-emitting LED light source |
| JP2008091862A (en) * | 2006-09-08 | 2008-04-17 | Sharp Corp | Nitride semiconductor light emitting device, and manufacturing method of nitride semiconductor light emitting device |
| JP2008117824A (en) * | 2006-11-01 | 2008-05-22 | Sharp Corp | Method of manufacturing nitride-based semiconductor element |
| DE102008019268A1 (en) * | 2008-02-29 | 2009-09-03 | Osram Opto Semiconductors Gmbh | Optoelectronic component and method for producing an optoelectronic component |
| WO2019055678A1 (en) * | 2017-09-13 | 2019-03-21 | Lares Research | Dental handpiece, motor and coupler with multi-wavelength light outputs |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3611069A (en) * | 1969-11-12 | 1971-10-05 | Gen Electric | Multiple color light emitting diodes |
| US4159452A (en) * | 1978-01-13 | 1979-06-26 | Bell Telephone Laboratories, Incorporated | Dual beam double cavity heterostructure laser with branching output waveguides |
| DE2822146C2 (en) * | 1978-05-20 | 1982-11-25 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Heterostructure semiconductor laser diode and method for manufacturing a heterostructure semiconductor diode |
| NL8005134A (en) * | 1980-09-12 | 1982-04-01 | Philips Nv | OPTICAL TRANSMISSION SYSTEM. |
| NL8101409A (en) * | 1981-03-23 | 1982-10-18 | Philips Nv | SEMICONDUCTOR LASER WITH AT LEAST TWO RADIATION BEAMS, AND METHOD OF MANUFACTURING THESE. |
| US4577207A (en) * | 1982-12-30 | 1986-03-18 | At&T Bell Laboratories | Dual wavelength optical source |
-
1984
- 1984-10-09 US US06/658,568 patent/US4605942A/en not_active Expired - Fee Related
-
1985
- 1985-09-27 EP EP85905162A patent/EP0197117B1/en not_active Expired
- 1985-09-27 JP JP60504594A patent/JPS62500415A/en active Pending
- 1985-09-27 WO PCT/US1985/001911 patent/WO1986002491A1/en active IP Right Grant
- 1985-09-27 DE DE8585905162T patent/DE3569635D1/en not_active Expired
- 1985-10-08 CA CA000492495A patent/CA1226929A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| WO1986002491A1 (en) | 1986-04-24 |
| JPS62500415A (en) | 1987-02-19 |
| US4605942A (en) | 1986-08-12 |
| EP0197117A1 (en) | 1986-10-15 |
| EP0197117B1 (en) | 1989-04-19 |
| DE3569635D1 (en) | 1989-05-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1226929A (en) | Multiple wavelength light emitting devices | |
| CA1139412A (en) | Light emitting diodes with high external quantum efficiency | |
| US5358880A (en) | Method of manufacturing closed cavity LED | |
| DE69927447T2 (en) | Device with an optical function and special connection electrodes | |
| US5497391A (en) | Monolithic array of independently addressable diode lasers | |
| US4884112A (en) | Silicon light-emitting diode with integral optical waveguide | |
| US4700210A (en) | Asymmetric chip design for LEDS | |
| IE53373B1 (en) | Semiconductor laser having at least two radiation beams,and method of manufacturing same | |
| US4547956A (en) | Process for producing a semiconductor laser with several independent wavelengths and laser obtained by this process | |
| US5408105A (en) | Optoelectronic semiconductor device with mesa | |
| US4967241A (en) | Semiconductor light emitting device | |
| US4367483A (en) | Optical semiconductor device | |
| US5710441A (en) | Microcavity LED with photon recycling | |
| JPS6120156B2 (en) | ||
| US4220960A (en) | Light emitting diode structure | |
| US6882672B2 (en) | Point emission type light emitting element and concentrating point emission type light emitting element | |
| US4374390A (en) | Dual-wavelength light-emitting diode | |
| US4912533A (en) | End face light emitting element | |
| US4019805A (en) | Optimized parabolic-index optical fiber communication system with incoherent light source | |
| JPS5839080A (en) | Light emitting diode | |
| JPS60154694A (en) | Semiconductor laser | |
| JPH06132563A (en) | Semiconductor light emitting device | |
| KR100284760B1 (en) | Semiconductor laser diode and manufacturing method thereof | |
| JPH06310755A (en) | Led array chip and fabrication thereof | |
| JP2595880B2 (en) | Method for manufacturing semiconductor optical coupling device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 20051008 |