Characterization of high-power quasi-cw laser diode arrays

Abstract

NASA's requirements for high reliability, high performance satellite laser instruments have driven the investigation of many critical components; specifically, 808 nm laser diode array (LDA) pump devices. Performance and comprehensive characterization data of Quasi-CW, High-power, laser diode arrays is presented.

Promoting Robust Design of Diode Lasers for Space: A National Initiative

“…The characterization methods are listed in Table 1. (Details of these measurement techniques and results can be found in reference [12].) These measurements establish a baseline for each device and are then used both for comparison to the same device at a later time and also against different devices.…”

“…The emphasis of the GSFC program is on 808-nm LDAs for pumping the Nd family of laser hosts [12], while the LaRC program focuses on 792-nm LDAs operating in the longpulse duration mode required for pumping 2-gm Tm-and/or Ho-based laser materials [13]. The test facility at JPL extends evaluation to single diode formats that address a wide range of wavelengths corresponding to the diverse nature of laser applications at NASA [14,15].…”

“…Details of measurements and instrumentation can be found in reference [16]. 12 operated in vacuum, 28 capable of thermal cycling, all capable of power cycling, all run in a laminar flow environment and all autonomously monitored and computer controlled. Using these facilities, 96 devices have been tested for over 50 million shots each, 47 devices over 500 million and several over 10 billion, logging a total 165 billion device shots (>520 billion bar shots).…”

Laser Diode Pump Technology for Space Applications

“…Samples of P-I and efficiency curves (left) and spectral measurements at three different currents (right). [22] 8. Temporally and Spectrally Resolved (TSR) measurement at maximum current A measurement of the temperature of the active region is an important parameter as the lifetime of LDAs decreases with increasing temperature.…”

“…Change in peak wavelength, full-width at half-maximum and temperature as a function of time at 100A, during a current pulse of 200 μs, derived from the temporally resolved data matrix. [22] Packaging-induced stress and defects have been found to play a significant role in LDA reliability and therefore their early detection is critical for device screening and space qualification. There are a number of non-destructive techniques available for that purpose such as micro-photoluminescence and photocurrent spectroscopy.…”