Laser Sources for Frequency Calibration of Far-Infrared Spectrometers

LongWave Photonics is proposing a novel DFB Quantum Cascade Lasernbsp;(QCL)nbsp;based on active cryogenic alignment of a grating to the gain chip, in ordernbsp;to achieve accurate frequency output (e.g. 4.744 THz).nbsp; Devices will be based on waveguides with loosely confined optical modes, resulting in highly symmetric output beams, and higher output power levels.nbsp; The devices will be suitable for use as either local oscillators, or as frequency references for spectrometers.nbsp; The second thrust of this proposal is in improving the frequency stabilization the QCLs.nbsp; LongWave is proposingnbsp;a robust optical frequency stabilization technique based on difference frequency generation of the THz QCL and a NIR pump wavelength.nbsp; The resulting QCL will be stabilized to lt;20 kHz linewidth, and will be capable of simultaneously stabilized several QCLs in the 2 to 5 THz frequency range.nbsp;nbsp;