Low SWaP Semiconductor Laser Transmitter Modules For ASCENDS Mission ApplicationsThe National Research Council's (NRC) Decadal Survey (DS) of Earth Science and Applications from Space has identified the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as an important atmospheric science mission. NASA Langley Research Center, working with its partners, is developing fiber laser architecture based intensity modulated CW laser absorption spectrometer for measuring XCO2 in the 1571 nm spectral band. In support of this measurement, remote sensing of O2 in the 1260 nm spectral band for surface pressure measurements is also being developed. In this paper, we will present recent progress made in the development of advanced transmitter modules for CO2 and O2 sensing. Advanced DFB seed laser modules incorporating low-noise variable laser bias current supply and low-noise variable temperature control circuit have been developed. The 1571 nm modules operate at >80 mW and could be tuned continuously over the wavelength range of 1569-1574nm at a rate of 2 pm/mV. Fine tuning was demonstrated by adjusting the laser drive at a rate of 0.7 pm/mV. Heterodyne linewidth measurements have been performed showing linewidth ~200 kHz and frequency jitter ~75 MHz. In the case of 1260 nm DFB laser modules, we have shown continuous tuning over a range of 1261.4 - 1262.6 nm by changing chip operating temperature and 1261.0 - 1262.0 nm by changing the laser diode drive level. In addition, we have created a new laser package configuration which has been shown to improve the TEC coefficient of performance by a factor of 5 and improved the overall efficiency of the laser module by a factor of 2.
Document ID
20120010475
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Prasad, Narasimha S. (NASA Langley Research Center Hampton, VA, United States)
Rosiewicz, Alex (EM4 Bedord, MA, United States)
Coleman, Steven M. (EM4 Bedord, MA, United States)
Date Acquired
August 26, 2013
Publication Date
April 23, 2012
Subject Category
Lasers And Masers
Report/Patent Number
NF1676L-14607
Meeting Information
Meeting: SPIE Defense, Security and Sensing 2012
Location: Baltimore, MD
Country: United States
Start Date: April 23, 2012
End Date: April 27, 2012
Sponsors: International Society for Optical Engineering