**
Semiconductor Lasers &
Quantum Wells**

Semiconductor lasers (or laser diodes, LD), first demonstrated in early
60s, were thought to be hardly suitable for any practical applications.
These days, the entire laser industry is classified by many as industry
of semiconductor lasers and all other types of lasers. By overall
compactness and wall-plug efficiency, no other laser source can compete
with laser diodes. Major milestones in the development of semiconductor
lasers include double heterostructure for separate optimization of
confinement of charge carriers in the active area and emitted light in
the guiding layer; extremely narrow active area (quantum well, QW) in
which quantization of motion of electrons and holes leads to a sharper
density of states distribution in the energy domain and eventually to
higher output efficiency; wavelength selection and tunability in lasers
with built-in diffraction gratings: distributed feedback (DFB) and
distributed Bragg reflectors (DBR) lasers; vertical cavity surface
emitting lasers (VCSEL) with extremely high modulation speed and optical
output matching the fundamental mode of a standard optical fiber;
quantum cascade (QC) lasers - well, these are not diodes anymore, - in
which efficient population of the top energy level and depopulation of
the bottom level are achieved through quantum tunneling resonances; and,
of course, introduction of new material systems that expand wavelength
range covered by semiconductor lasers.

Our contribution to the
field comprises the concept of binary superimposed gratings (BSG) for
widely tunable semiconductor lasers. The technology has been patented
and licensed to Nortel Networks. Earlier work includes research on
lateral current injection lasers, studies of fine spectral modulations
due to tunneling coupling between the guided mode in a laser and the
substrate modes, development of high-power aluminum-free pump lasers,
lasers with external resonators, and spectroscopic characterization of
quantum well structures.

**
Publications:**

**US Patent 6,141,370 **
(2000)** **Superimposed Grating WDM Tunable Lasers; Licensed to
Nortel Networks

[51]
**IEEE J. of Selected Topics in Quantum Electronics **(1999), “Ion
implanted GaAs/InGaAs lateral...”

[49]
**IEEE J. of Quantum Electronics** (1998), “Design of
widely tunable semiconductor lasers and the…”

[48]
**SPIE Proceedings**
(1998), “Binary superimposed gratings for tunable and multiwavelength...”

[47]
**Compound Semiconductors** (1998), “Ion implanted
GaAs/InGaAs lateral injection ridge QW laser..."

[46]
**IEEE J. of Quantum Electronics** (1997),
“Investigations of the spectral characteristics of 980-nm..."

[45]
**Semiconductors **
(1997), “A study of the excitonic characteristics in heterostructures
with quantum..."

[44]
**Quantum Electronics** (1997), “Semiconductor lasers
with tunnel-coupled waveguides emitting at the..."

[43]
**Quantum Electronics** (1996), “Single-mode emission
from injection lasers with a trapezoidal active...”

[42]
**Semiconductors** (1996), “Photomodulation
spectroscopy for determining the total exciton absorption...”

[41]
**Physics of low-dimensional structures** (1995),
“Phase space filling in quantum well filled by 2D...”

[40]
**SPIE Proceedings** (1995), “Calculation of exciton
suppression in quantum well filled by 2D electron...”

[39]
**SPIE Proceedings** (1995), “Modulation spectroscopy
for determination of integral excitonic absorption...”

[38]
**Advanced Materials in Optics, Electrooptics and
Communication Technologies** (1995) “InGaP…”

[37]
**Quantum Electronics** (1994), “Lasers emitting at a
wavelength of 0.98 um, constructed from InGaP… “

[36]
**Soviet Lightwave Communications** (1993), “InGaP/GaAs/InGaAs
quantum well lasers prepared by…”

[35]
**
Soviet Lightwave Communications** (1992), “Study of In(x)Ga(1-x)As/GaAs
single quantum well…”

[34]
**Soviet Physics. Semiconductors** (1992)
“Determination of the homogeneity of quantum wells in the…”

[33]
**Soviet Physics. Semiconductors** (1991),
“Calculation of the exciton parameters in stressed quantum…”

[17]
**Soviet
J. of Quantum Electronics** (1988), “Radiation sources for fiber-optic
communication lines with…”

[16]
**Soviet Technical Physics Letters** (1987),
“Single-frequency semiconductor laser with lambda=1.3um…”