Laser system and method with temperature controlled crystal
AssigneeInternational Business Machines Corporation
InventorsDonald S. Bethune, William J. Kozlovsky
Life of this patent
Estimating the term…
Abstract
A laser produces a light beam which is passed through a nonlinear crystal along a beam path. The noncritical phase matching axis of the nonlinear crystal is offset at a slight angle from the beam path. The angle of exit of the second harmonic light from the nonlinear crystal varies with the temperature of the crystal. A segmented photodetector detects this beam angle and generates a temperature error signal. A temperature control element receives a temperature error signal and causes the temperature of the crystal to be adjusted.
Claims14
A nonlinear crystal system comprising:
- a radiation source for providing a primary beam;
- a nonlinear crystal for receiving the primary beam along a beam path axis, a noncritical phase matching axis of the nonlinear crystal oriented nonparallel to the beam path axis;
- a beam angle detection means for receiving an output beam from the nonlinear crystal, detecting an output beam angle and generating a temperature error signal;
- and
- a crystal temperature adjustment means connected to the beam angle detection means and the crystal for adjusting the temperature of the crystal responsive to the temperature error signal.
A nonlinear crystal system comprising:
- a radiation source for providing a primary beam;
- a nonlinear crystal for receiving the primary beam along a beam path axis, a noncritical phase matching axis of the nonlinear crystal oriented nonparallel to the beam path axis;
- a segmented optical detector for receiving an output beam from the nonlinear crystal;
- a temperature control circuit connected to the optical detector for generating a temperature error signal;
- a crystal temperature adjustment means connected to the temperature control circuit and the crystal for adjusting the temperature of the crystal responsive to the temperature error signal.
A nonlinear crystal system comprising:
- a laser for providing a first frequency light beam;
- a resonator for receiving the first frequency light beam and resonating the first frequency light beam along a beam path;
- a nonlinear crystal located within the resonator for converting the first frequency light beam to a second frequency light beam, a nonlinear crystal oriented with its noncritical phase matching axis nonparallel to the beam path;
- a beamsplitter for receiving the second frequency light beam from a nonlinear crystal;
- a photodetector having a first and a second segment for receiving a portion of the second frequency light beam from the beamsplitter;
- a temperature control circuit connected to the photodetector for detecting the difference in the amount of light striking the first and second segments and generating a temperature error signal responsive thereto;
- and
- a crystal temperature adjuster connected to the crystal and the temperature control circuit for adjusting the temperature of the crystal responsive to the temperature error signal.
A method for crystal temperature control comprising the steps of:
- generating a radiation beam;
- passing the radiation beam through a nonlinear crystal along a beam path which is slightly offset from a noncritical phase matching axis of the crystal;
- detecting an angle at which the radiation beam exits the crystal;
- and
- adjusting the temperature of the crystal responsive to the measured angle.
A nonlinear crystal system comprising:
- a radiation generation source for providing a primary beam;
- a nonlinear crystal for receiving the primary beam along a beampath axis, a noncritical phase matching axis of the nonlinear crystal oriented nonparallel to the beampath axis;
- a beam angle detection means for receiving a first portion of an output beam from the nonlinear crystal, detecting an output beam angle and generating a temperature error signal;
- a crystal temperature adjustment means connected to the beam angle detection means and the crystal for adjusting the temperature of the crystal responsive to the temperature error signal;
- an optical recording medium;
- an optical transmission means for receiving a second portion of said output beam from the nonlinear crystal and directing said second portion to the optical recording medium;
- and
- optical reception means for receiving a reflected light beam from the optical recording medium and providing a data signal responsive thereto.
Dependencies are inferred from the claim text.