摘要:
A tunable optical resonator whose resonance frequency is determined by a light signal introduced into the resonator. The resonator includes an optical cavity having a first mirror and a second mirror. The first mirror and second mirror are supported relative to one another such that the distance between the first and second mirrors may be altered by applying a force to said second mirror thereby altering the resonance frequency of said cavity. The resonator includes a light input port for receiving a tuning light signal, and a light signal generator for generating the tuning light source. The tuning light signal is introduced into the optical cavity such that the tuning light signal is reflected between the first and second mirrors. In the absence of the tuning light signal, the resonator has a resonance characterized by a resonance response curve centered at &lgr;0. The tuning light signal has a wavelength &lgr;1 within said resonance response curve and sufficient power to cause said resonance response curve to shift such that the resonance response curve is now centered at &lgr;2, where &lgr;2>&lgr;1. In one embodiment of the invention, a circuit for monitoring the light leaving the resonator is utilized to control the wavelength and/or amplitude of the tuning light signal such that the light leaving the resonator has a predetermined wavelength.
摘要:
A tunable optical cavity constructed from a fixed mirror and a movable mirror is disclosed. A circuit applies an electrical potential between first and second electrically conducting surfaces thereby adjusting the distance between the fixed and movable mirrors. The fixed mirror and the moveable mirror are positioned such that the mirrors form the opposite ends of the optical cavity. The distance between the fixed mirror and the moveable mirror is a function of the applied electrical potential. The thermally induced vibrations are reduced by utilizing an electrical feedback circuit that measures the distance between the mirrors. The feedback circuit dynamically changes the potential between the substrate and the support member so as to reduce fluctuations in the cavity resonance frequency.
摘要:
A self-tuning mode locked semi-conductor laser automatically adjusts itself to produce short (less than 200 ps and preferably less than 50 ps) stable optical pulses. Tuning is achieved by means of a feedback loop which includes a spectrum analyzer (18) which receives a small amount of the optical output of the laser and monitors the spectral wavelength, spectral width or spectral shape of the output. A controller (19) is connected to said analyzer and produces a control signal based on said spectral information. The control signal causes adjustment of one or more parameters influencing operation of said laser, such as frequency or power of an RF drive signal, level of dc bias, cavity length, for example, in order to produce said short stable pulses.
摘要:
Disclosed is a time division multiplexed optical communication system that is capable of operation at relatively high bit rates and that is relatively stable and immune to crosstalk and noise. The system comprises receiver means wherein the timing signal for demultiplexing is derived from the fully multiplexed optical pulse stream by means that comprise a narrow band receiver and timing means that produce a lower-frequency timing signal from the output of the narrow band receiver. The timing signal is used to drive one or more optical switches. In one embodiment of the invention the receiver means have a binary-tree architecture and the timing signals are substantially sinusoidal. In another embodiment the receiver means have a linear-bus architecture and the timing signals are pulse-like.