Amendment_II.docx

AMENDMENT II: INGAAS IMAGING CAMERA – 1333ND18QNB620268

The purpose of Amendment II is to respond to vendor questions submitted regarding the minimum requirements as follows:

MINIMUM REQUIREMENTS:

2. The InGaAs imaging camera shall have the quantum efficiency between 1000 nm and 1600 nm equal to or greater than 75%.

Question: Since the InGaAs Imager will be mainly used at 980nm, 1300nm and 1550 bands. How do you measure the QE between 1000nm and 1600nm continuously?

Answer: Quantum efficiency is measured by the ratio of electrons generated from the impinging photons on the sensor. NIST has several tunable sources spanning the specified spectral range.

10. The InGaAs imaging camera shall allow for integration times between one microsecond and 100 seconds.

Question: Would you accept InGaAs imager with integration time between 20 microsecond and 100 seconds?

Answer: No, the minimum requirement is as stated

12. The InGaAs imaging camera detector chip shall be thermoelectrically cooled to a temperature below 270 K, resulting in dark current less than 15000 electrons per second.

Question: What's the maximum ambient temperature to operate this InGaAs imager? Is it at control lab environment (20 - 30-degree C)?

Answer: NIST plans to operate in a controlled laboratory environment between 20 C and 25 C

14. The InGaAs imaging camera noise shall be less than 15 analog-to-digital units (high gain) and less than 10 analog-to-digital units (low gain) for an integration time of 0.1 ms.

Question: Could you please explain the reason using "Analog-to-Digital units" for noise specs? A camera noise spec is typically quoted in electron or photons either in low gain or in high gain mode.

Answer: NIST specified noise in terms of the camera gain

This Amendment results in no change to the solicitation terms and conditions or minimum requirements as currently stated in Amendment I. The due date/time for quotations remains unchanged.