Project Title:
Tunable, Infrared, Diode-Laser Arrays for High-Performance Spectrometers
08.08-3666
910319
Tunable, Infrared, Diode-Laser Arrays for High-Performance Spectrometers
Electro-Optek Corporation
3152 Kashiwa Street
Torrance
CA
90505
C.F.
Huang
213-534-3666
JPL
NAS7-1184
146
08.08-3666
910319
Abstract:
Tunable, Infrared, Diode-Laser Arrays for High-Performance Spectrometers
Double heterojunctions (DH) PbS/PbSSe/PbS diode laser arrays will be developed as
tunable infrared radiation sources covering the 3 to 5 mm waveband. Using molecular
beam epitaxy (MBE) bandgap engineering, the PbSSe epitaxial layer will be tailored
for a specific wavelength and engineered as an active well region sandwiched between
two PbS cladding layers. The injected electron-hole pairs will be confined to this
well region for higher operating temperature and lower threshold current in lasing.
Two PbS/PbSSe superlattices, also fabricated by MBE, will be used as distributed
Bragg reflectors (DBR), sandwiching the DH laser to form the resonance cavity. Thus
the laser will emit radiation perpendicular to the surface of the substrate, allowing
a simple configuration for structuring a two-dimensional array of lasers emitting
from the surface. The multiple-layer growth will be made on a silicon (Si) substrate
buffered with a mixed-fluoride epitaxial layer to match the lattices of Si and PbS/PbSSe/PbS
laser structure. Lattice matching between the DBR and the DH structures will be made
by controlling the periodicity and composition of the interfacial defects, junction
leakage, and nonradiative carrier absorption, leading to an increase in lasing efficiency
and device yield. Phase I will model and design the DH structure; design the MBE
sources and fixtures needed for epitaxy; demonstrate the feasibility of buffer epitaxy;
and demonstrate the feasibility of PbSSe epitaxy on buffered Si. Phase II will be
devoted to the development of the DBR and the fabrication of the DH laser structure.
Applications may result in electronic countermeasures, active imaging, missile guidance,
optical computing, and designators.
laser array, tunable laser, PbSSe, double heterojunction, surface emitting laser,
molecular epitaxy