Electro-Optic Modulator and Method
Patent, Filed 31 Jul 96, patented 21 Sep 99
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
An optical intensity modulator which uses a Sagnac interferometer having an electro-optic phase modulator therein. An electric modulation signal is delivered to the modulator, and the latter is selected so that the phase velocity of optical and electrical signals are comparable in it. This causes the optical signal from one interferometer arm to copropagate through the modulator with the electrical signal, increasing interaction time with it, and causes the optical signal from the other arm to counterpropagate with the electric signal, reducing interaction time. In addition to phase modulating the optical signals by the electrical signal, the electro-optic effect in the modulator phase shifts the optical signals with respect to one another, permitting them to form a non-zero interference pattern, whose intensity corresponds to the electrical signal. In one embodiment, the interferometer has a non-reciprocal device to impose a constant phase difference between the counterpropagating optical signals, which permits one to place the systems setpoint to any arbitrary point on the systems transmissivity versus phase response. e.g. large signal andor linear response.
- Electrooptical and Optoelectronic Devices
- Non-Radio Communications