[li] 4,340,272 [45] Jul. 20, 1982
[54] LIGHT INTENSITY MODULATOR IN AN INTEGRATED OPTICAL CIRCUIT WITH FEEDBACK MEANS
[75] Inventors: Michel Papuchon; Claude Puech,
both of Paris, France
[73] Assignee: Thomson-CSF, Paris, France
[21] Appl. No.: 136,474
[22] Filed: Apr. 2, 1980
[30] Foreign Application Priority Data
Apr. 3, 1979 [FR] France 79 08372
[51] Int. C1.3 G02B 5/174
[52] U.S. CI 350/96.14
[58] Field of Search 350/96.11, 96.12, 96.13,
350/96.14
[56] References Cited
U.S. PATENT DOCUMENTS
3,944,812 3/1976 Hattori et al 350/96.14
3,995,311 11/1976 Taylor 350/96.14
4,070,094 1/1978 Martin 350/96.14
4,211,467 7/1980 Cross et al 350/96.14
The invention relates to a light intensity modulator, in integrated optics and an integrated optical circuit comprising such a modulator.
The modulator comprises a two-arm interferometer in which there is created by electro-optical effect, a phase shift controlled by a modulating voltage between the light waves propagated in the two arms. It is characterized by a feedback loop comprising a light separator placed on the output guide of the interferometer, and a photodiode collecting the fraction of output intensity from the separator and supplying an electric voltage which is superimposed in the interferometer on the modulating voltage. Thus linearization of the output intensity-modulating voltage response curve is obtained.
11 Claims, 8 Drawing Figures
