Temperature compensation for acousto-optc devices

An acousto-optic tunable device comprising:

• a) an acousto-optic substrate;
• b) an acoustic wave transducer positioned on the acousto-optic substrate;
• c) a temperature sensor that is positioned in thermal communication with the acousto-optic substrate, the temperature sensor generating an electrical signal at an output that is related to a temperature of the acousto-optic substrate;
• d) a processor having an input that is electrically coupled to the output of the temperature sensor, the processor generating a control signal at an output in response to the electrical signal generated by the temperature sensor;
• and
• e) an oscillator having a control input that is electrically coupled to the output of the processor and having an output that is electrically coupled to the acoustic wave transducer, a frequency of the oscillator being changed in response to the control signal in order to maintain phase-matching criteria of the acousto-optic tunable device as the temperature of the acousto-optic substrate changes.

A device for maintaining phase-matching criteria in an acousto-optic device during temperature variations, the device comprising:

• a) means for measuring a temperature of the acousto-optic device;
• b) means for generating a control signal in response to the measured temperature;
• and
• c) means for changing the frequency of a signal applied to an acoustic wave transducer positioned in the acousto-optic device in response to the control signal, the frequency of the signal being chosen to maintain the phase-matching criteria of the acousto-optic device.