LASER Diodes and Arrays
ATC-Semiconductor Devices manufactures multi-mode high power laser diodes
with CW output power of 500 mW ... 8 W, and QCW laser arrays (bars) with peak
output power up to 150 W.
The ATC series laser diodes and arrays are manufactured on the base of MBE
or MOCVD grown InAlGaAs quantum well heterostructures. These technologies provide
a very accurate control of the chemical composition and grown layer thickness
and ensure high reproducibility of device parameters. Application of quantum
well structures (active layer thickness of 70-150 angstrom) provides low threshold
current densities and high optical output power. Lasers are soldered on to the
heat sink with the epitaxial layers down, which ensures efficient heat removal
and provides high optical output power. ATC-SD carries out testing of each device
(250 to 500 hours of operation in CW mode) and one-off certification after the
test. This procedure ensures the selection of highly reliable samples.
Lasers can be manufactured either on open heat sink (C-mount, L-package) or
in hermetic cases (ATC package ànd TO-3 package). Lasers of the "open heat sink",
"C-mount" and "L-package" type allow different manipulations with the laser
crystal. They are preferable if the user carries out scientific investigations
and encapsulates the entire module (laser diode and radiator) by himself. The
ATC package is a hermetically sealed case with a flat output window. This unit
allows operation without a complementary heat sink in a pulsed mode and in some
cases, in a CW mode. The small heat resistance of the ATC package provides a
low temperature difference between external package surface and laser crystal.
The TO-3 package includes a Peltier thermocooler and thermistor, which allows
to maintain constant operation temperature. Being adjusted and completely compatible
to the worldwide standards, our version of TO-3 package has a detachable mounting
ring. This gives a higher variety of possible applications and allows to achieve
a higher density of the device design in the user's applications.
The ATC and TO-3 packages may contain a monitor photodiode as an option, which
ensures stabilization of the radiation power. Photodiode characteristics are
linear with a wide power range. The photodiode operates without opposite bias
and the response time is about 50 ns. The photodiode current is a relative value
which may be used as a feedback for control and adjustment of the emitted optical
power. The maximum photodiode current is 10 mA.
All packages may contain a cylindrical microlens as an option, which reduces
the radiation divergence in 20 times (in one plane). With this option customer
can work without additional optical systems or can use an inexpensive long focus
The L-package is used for laser arrays. The bar emitting area width is more
than 90% of the heat sink width, which allows to use of several laser bars simultaneously
for DPSSL pumping.