We report on recent progress made in the development of highly compact, single mode, distributed
feedback laser (DFB) seed laser modules with integrated drive electronics for lidar and spectroscopy
applications from space based platforms. One of the intended application of this technology is in the
NASA’s Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.
NASA Langley Research Center (LaRC) is working on a prototype laser based spectroscopy system
for simultaneous measurement of CO2 and O2 for planned Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission application. For this purpose, 1571 nm spectral
band for CO2 sensing and 1262 nm spectral band for oxygen sensing have been selected. In this
paper, we discuss recent progress made in the development of single mode, compact and stable, seed
laser technologies for CO2 and O2 transmitters with focus on linewidth and noise measurements. The
1571 nm and 1262 nm DFB laser modules with integrated drive electronics have advanced current
and temperature drivers built into them. A combination of temperature and current tuning allows
coarse and fine adjustment of the diode wavelengths. The current tuning was demonstrated at a rate
of ~0.7 pm/mV over a working range of ~1 V for a total of 0.7 nm. Also, temperature tuning at a
rate of ~2 pm/mV over a working range of ~1 V for a total wavelength range of ~2 nm was
demonstrated. The current tuning was performed at a rate of up to 200 kHz allowing rapid
adjustment and dithering of the laser frequency. Furthermore, the best performance of laser
linewidth observed was ~11 kHz with frequency stability <10 MHz over 1 hour period. The microcooler
arrangement embedded inside these modules has provided significant reduction in power
consumption. The electronics has been designed, prototyped and tested using space-qualified
components within a hermetically sealed package of volume less than 2" x 2" x 0.5".
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.
NASA Langley Research Center (LaRC) is working on a prototype laser system for simultaneous
measurement of CO2 and O2 for planned Active Sensing of CO2 Emissions over Nights, Days, and
Seasons (ASCENDS) mission application. For this purpose, 1571 nm spectral band for CO2 sensing
and 1262 nm spectral band for oxygen sensing have been selected. In this paper, we discuss recent
progress made in the development of single mode, compact and stable, seed laser technologies for
CO2 and O2 transmitters. In particular, the development of an advanced distributed feedback laser
(DFB) module master oscillator operating at 1571 nm, that is efficiently coupled to drive electronics
and nano-cooling scheme in a single hermetically sealed package of volume less than 2" x 2" x 0.5", is presented.
This work has sought to develop distributed feedback (DFB) diode-laser concepts and technologies
necessary to facilitate NASAs upcoming Active Sensing of CO2 Emissions over Nights, Days, and
Seasons (ASCENDS) mission. Specifically, a modified-COTS DFB laser module, incorporating a low-noise
variable laser bias current supply and low-noise variable temperature control circuit, has been
developed. Prototype hardware has been built and tested.
Conference Committee Involvement (5)
Optical Technologies for Arming, Safing, Fuzing, and Firing VI
2 August 2010 | San Diego, California, United States
Photonics in the Transportation Industry: Auto to Aerospace III
5 April 2010 | Orlando, Florida, United States
Optical Technologies for Arming, Safing, Fuzing, and Firing V
5 August 2009 | San Diego, California, United States
Optical Technologies for Arming, Safing, Fuzing, and Firing IV
13 August 2008 | San Diego, California, United States
Optical Technologies for Arming, Safing, Fuzing, and Firing III
29 August 2007 | San Diego, California, United States
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