Stable Diode Laser Source at 1.6 Micron

OPTRA will demonstrate the feasibility of stabilizing the wavelength and frequency of a 1.6 micron laser diode to an accuracy of 1 part in 109 (200 kHz). Key to the approach is the use of a frequency discriminator based on the zero phase point of the anomalous dispersion curve of a gas absorption line (in this case CO2). This phase is measured, without the need of any frequency dither, through use of an ultra stable interferometeric phase without being affected by laser intensity noise. The technique can also be adapted to any laser wavelength presently commercially available or future ones under development. The design will be compact and require little electrical power, likely less than 1 watt and which includes that required for a TE cooler/heater to maintain the operating point of the laser diode. The device will produce more than 1 mWatt of optical power from a single mode polarization preserving optical fiber.