국내 최대 기계 및 로봇 연구정보

기술보고서

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타이틀	Low SWaP Semiconductor Laser Transmitter Modules For ASCENDS Mission Applications
저자	Prasad, Narasimha S.;; Rosiewicz, Alex;; Coleman, Steven M.
Keyword	AMBIENT TEMPERATURE;; CARBON DIOXIDE;; CARBON MONOXIDE;; CHIPS (ELECTRONICS); CIRCUIT BOARDS;; CONTINUOUS WAVE LASERS;; DETECTION;; EARTH SCIENCES;; ELECTRIC POTENTIAL;; FREQUENCY DISTRIBUTION;; MODULES;; OUTPUT;; SEMICONDUCTOR LASERS;; TRANSMITTERS;; WAVELENGTHS
URL	http://hdl.handle.net/2060/20120010475
보고서번호	NF1676L-14607
발행년도	2012
출처	NTRS (NASA Technical Report Server)
ABSTRACT	The 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.