The MVACS Tunable Diode Laser Spectrometers
Two independent tunable diode laser spectrometers are resident aboard the Mars Polar Lander as part of the Mars Volatile and Climate Surveyor payload.
Engineering topics
Publications and source records attributed to Forouhar, S..
Two independent tunable diode laser spectrometers are resident aboard the Mars Polar Lander as part of the Mars Volatile and Climate Surveyor payload.
These experiments demonstrate that COEOs are promising compact sources for generating low jitter optical pulses and low phase noise RF/millimeter wave signals.
The continued need for increased bandwidth is driving the pursuit of both increased speed in TDM and more channels in WDM for fiber optic communication systems.
In this paper, we will present the design and fabrication of an integrated semiconductor laser/modulator using the identical active layer approach on InGaAsP/InP material.
We present experimental results of coupled opto-electronic oscillators (COEO) constructed with a semiconductor optical amplifier based ring laser, a semiconductor Fabry-Perot laser, and a semiconductor colliding pulse mode-locked laser.
Alternative approaches for developing 2.0- 2.5 um single frequency semicondoctor lasers are reviewed.
The current status of tunable diode lasers (TDLs) for spectroscopy and metrology systems is reviewed.
Colliding pulse mode-locked laser arrays are being developed at 20 GHz for WDM applications. Arrays with 5 wavelengths in the EDFA gain bandwidth have already been demonstrated, with the final goal being a packaged, 10 wavelength mode-locked laser array.
The current status of III-V tunable diode lasers (TDLs) emitting between 1-5 mue wavelengths for spectroscopy and chemical analysis is described.
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Wavelength division multiplexed (WDM) systems place stringent requirements on the absolute wavelength and wavelength spacing of the elements in laser arrays. Ridge waveguides (RW) show excellent potential for practical implementation due to their simple fabrication with relaxed fabrication tolerances, high reliability and good performancce. An analysis of the fabrication tolerances for RW and buried heterostructure (BH) devices is performed, showing the advantages offered by the ridge design.
InGaAs/InGaAsP strained quantum well buried heterostructure and distributed feedback lasers emitting at wavelengths as long as 2.06 micrometers with low internal loss and threshold currents have been demonstrated for the first time. The room and high temperature characteristics and the threshold gain are discussed.
Single-mode distributed feedback (DFB) laser diodes typically require a two-step epitaxial growth or use of a corrugated substrate. We demonstrate InGaAs-GaAs-AlGaAs DFB lasers fabricated from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etehed along the sides of the ridge. A CW threshold current of 25 mA and external quantum efficiency of 0.48 mW/mA per facet were measured for a 1 mm cavity length device with anti-reflection coated facets. Single-mode output powers as high as 11 mW per facet at 935 nm wavelength were attained. A coupling coefficient of at least 5.8/cm was calculated from the subthreshold spectrum taking into account the 2% residual facet reflectivity.
This project is to develop the components and subsystems for the.
A novel technique to achieve stable single-mode oscillation laser diodes that eliminates the need for epitaxial regrowth has been developed and demonstrated at JPL.
Results are presented on laterally-coupled distributed feedback (LC-DFB) ridge laser diodes. The epitaxial regrowth required in most distributed feedback devices is eliminated by using lateral evanescent coupling of the field to gratings etched along the sides of the ridge.
Single-mode distributed feedback (DFB) laser diodes typically reqire a two-step epitaxial growth or use of a corrugated substrate. We demonstrate InGaAs-GaAs-AlGaAs DFB lasers fabricated from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etched along the sides of the ridge.
The first low threshold continuous operation of InGaAs strained layer quantum well lasers at about 2.0 microns is reported. The threshold current density of 5-micron wide and 1.5 mm long ridge waveguide lasers was less than 380 A/sq cm. The external differential quantum efficiency of 1 mm long lasers was as high as 15 percent and laser operation was observed at temperatures as high as 50 C. The lasers are characterized by T(0) = 54 C which is the highest characteristic temperature ever achieved at this wavelength in any material system.