STATEMENT OF WORK.pdf

Purchasing Request Engineering Model Intra-Cavity Optical Parametric Oscillator

Laser Electronics Assemblies

Requested by:

Xiaoli Sun 9/18/2023

Items to Purchase:

Engineering Model Intra-Cavity Optical Parametric Oscillator (IOPO) Laser Electronics Assemblies

Qty. 2 each (for driving two individual lasers)

Deliver to:

Xiaoli Sun

NASA GSFC

Code 698 B33/D424 8800 Greenbelt Rd.

Greenbelt, MD 20771 xiaoli.sun-1@nasa.gov

(301) 614-6732

Statement of Work (SOW)

Background NASA GSFC is conducting a pre-phase-A study for the next lunar orbiting mission called Lunar Exploration and Science Orbiter (LExSO). One of the major payload instruments is a multi-wavelength lidar called Spectroscopic Infrared Reflectance and Altimetry Lidar (SpIRAL). It uses several intra-cavity optical parametric oscillator (IOPO) lasers, each producing three wavelengths, one at 1.064 micron, one at 1.6-micron, and and at 3-micron. Each IOPO laser consists of a diode-pumped Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, similar to the ones used in earlier space lidars.

A non-linear crystal is used to convert part of the 1.064-micron laser light into the other two wavelengths. Each IOPO has a slightly different laser wavelengths in the 1.6 and 3-micron bands. The basic IOPO laser design was from our 2019 Discovery proposal for the Lunar Volatile Orbiter (LVO). The LExSO lidar is similar to the LVO lidar and has a new burst operation mode to increase the ground sampling rate for selected sites. Space Power Electronics, Inc. (SPEI) developed the laser electronics for our LVO lidar with heritage from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) mission. We now asking them to upgrade the design with burst operation mode to increase the laser pulse rate from 100 Hz to 250 Hz for a few seconds at a time.

Scope: The contractor shall design, fabricate, test, and deliver an engineering model laser electronics circuit assembly that is capable of driving two IOPO lasers at 100 Hz

Laser Electronics Assemblies nominally and 250 Hz for up to 10 seconds. The laser electronics design shall be compatible with the earlier ones developed for the IOPO lasers on the LVO mission proposal. The contractor shall assist the Design Interface to design the mechanical housing for the laser electronics that fits in to the current instrument framework.

Period of Performance Six months after receipt of order (ARO)

Deliverables

(1) Engineering model unit of LExSO laser electronics, two each.

(2) Interface control document.

Specifications

Input Power Requirements

1. 28 Volt input to power.

2. Total average power consumption of less than 35 Watts (at 100Hz nominal pulse rate).

Output Current Pulse Requirements

1. Nominal current pulse peak of 100A

2. Maximum pump pulse width of 200us

3. Compliance voltage of 8 volts.

4. Slew rate for both rise and fall of pulse >15A/us.

5. Maximum repetition rate of 250Hz.

Output TEC Control

1. TEC control capable of handling a maximum voltage of 6 Volts and 4A.

2. Nominal setpoint of temperature control 18°C

Signal Input Requirements

1. Laser Enable input that is active low to allow the laser to be fired.

2. Laser Trigger input that is active low with duration of the trigger signal equal to the pump pulse width.

3. Laser current to allow for adjusting the current of the pump pulse from 10‐120A

4. TEC setpoint adjust to allow for adjusting the setpoint of the TEC from 16‐22°C.

5. Pump pulse termination. Signal input that will terminate the pump pulse if it is received before the end of the laser trigger being active.

Signal Output Requirements

1. Cap bank voltage monitor that is an analog output.

2. Laser current monitor that is an analog output.

3. Thermistor reading from inside the laser electronics.

4. Over current error flag

5. Over voltage error flag

6. POR error flag

7. Current pulse duration digital signal

Laser Electronics Assemblies

Operational Requirements

1. Radiation total dose of 20 Krad (incl RDF 2)

2. Operation temperature 18 +/‐ 2C

3. Survival temperature range‐20 to +55 °C