AMENDMENT TO SOLICITATION HIGH FINESSE DUAL WAVELENGTH REFERENCE CAVITY

CLARIFICATION/QUESTIONS AND RESPONSES AND EXTENSION OF RESPONSE TIME

Questions:

Request for more details about the product requirements:

• The input signal (light): free-space input or fiber input?
• If free-space input, then the light beam size, collimated or divergent one?
• For the Photodetectors, any requirements on the speed of the response (bandwidth)? Noise requirement, ….

Response:

A fiber input to the collimator assembly modules is specified in A.12 of the requirements document. Since the modules must be pre-aligned, the fiber input that is used for alignment should remain attached to the system and be included with it. The contractor is responsible for mode matching the light from the fiber into the optical cavity (or cavities) using a set of lenses and configuring additional optics specified in A.12 and A.13 to generate Pound-Drever-Hall locking signals.

The photodetectors must have a bandwidth sufficient for Pound-Drever-Hall locking to the optical reference cavity, at least 10 MHz. The input current noise for the photodetectors should be < 7 pA/Sqrt(Hz) (which is approximately less than 14 pW/Sqrt(Hz) of noise equivalent power).