Invited papers 1, 7, 19
Contributed paper 35, 49, 57, 67, 75, 83, 91
Issues relating to fabrication of
VLWIR HgCdTe detectors
with high performance and uniformity are reviewed. The primary
operative in the activation of p type dopants in HgCdTe is discussed
with implications for fabrication of high performance detectors. Origin
of native defect related deep centers in limiting the
lifetime is explored.
Features of diode lasers
pertinent to their application
in pumps for solid slate lasers and erbium-doped fibre amplifiers
are reviewed. Among them the factors restricting diode laser brightness
and output power are discussed more in detail. Design and some
of heterostructures used in fabrication of laser pumps for solid state
lasers and EDFAs are described. Al-free lasers proved to be more
to the catastrophic optical mirror damage and are discussed more
Broad area lasers, 1-D bars and 2-D arrays are surveyed and some
relevant to EDFA application are made. The paper is concluded with
of diode laser designs capable to provide the output beam of a better
quality. In this context ROW and ARROW array's as well as MOPA and
structures are shortly described.
Progress in technology and
construction of diode-pumped
laser made in the 80's caused renewed interest in diode pumping of
media of solid-state lasers (DPSSL -Diode Pumped Solid State Laser) and
next their rapid development. At present, DPSSL are commonly applied in
medicine and industry.
The paper presents advantages of such excitation and significant improvement in generation efficiency, longer service life of devices, smaller dimensions of quantum generators and theirs power suppliers. Special attention was paid to the possibility of application of new active media (new neodymium doped hosts), including ytterbium (Yb) doped media, that have perfect functional parameters with diode pumping. Fundamental configurations of active media and their excitation methods were described. A "slab" type geometry used for high-power lasers was distinguished. It was shown that construction of, so-called, microlasers is possible when diodes are used as pumps of solid state lasers. Microlasers can generate strictly monochromatic radiation (i.e., generate only one longitudinal mode). These lasers can be used for rangefinder transmitters and radars with heterodyne detection – new type devices applicability range of which is difficult to predict. Microlasers can be also used as frequency and length standards. A group of fibre lasers was considered and their unusual possibilities were described, among others generation of beams of high quality (M2 ~1) and high-power (1 kW). The examples of construction of high-power DPSSL (3.5 kW) were presented.
Strained layer InGaAsIGaAs SCH
SQW (separate confinement
heterostructure single quantum well) lasers were grown by a
epitaxy <MBE). Highly reliable CW (continuous wave) 98O-nm.
pump lasers were fabricated in stripe geometry using Schottky isolation
and ridge waveguide construction. Threshold current densities of the
of Jth =280 A/cm2 (for the resonator length L = 700 urn) and
efficiency h = 0.40 W/A (41%) from one mirror were obtained. The record
wall-plug efficiency for AR/HR coated devices was equal to 54%.
estimations of above parameters. obtained by numerical modelling of
were Jth = 210 A/cm2 and h = 0.47 W/A from one mirror, respectively.
studies revealed that uncoated and AR/HR coated devices did not show
appreciable degradation after 3000 hr of CW operation at at
sink temperature at the constant optical power (50 mW) conditions.
Recent trends in optoelectronics
tire towards small solid
stale lasers pumped by laser diodes. The paper describes efforts to
material basis for the development of this branch of optoelectronics.
crystal growth and properties of many compounds acting as active laser
or self-frequency doubling materials, passive modulators, nonlinear
materials, and acousto-optic materials are discussed, including yttrium
aluminium garnet with high neodymium concentration, vanadates, borates.
and double tungstates.
The interest in increasing signal
speed, lowering optical
losses and reducing power requirements led to the integration and
of the optoelectronics components. Planar optical devices play an
important role as the components for fibreoptic communication and
computing systems. Their purpose is to couple, switch, modulate,
or generate optical signal. Recent important development is successful
operation of planar waveguide amplifiers and lasers that could be
coupled to fibre components. Several waveguide fabrication techniques
employed depending on host material, including semiconductor materials,
dielectric crystals and glasses.
In this work the basic problems related to active waveguide fabrication and properties will be discussed. We also report the spectroscopic and laser properties of the Nd3+:YAG/YAG epitaxial thin films obtained in ITME laboratory in Warsaw
The paper presents results of
investigations on generation
of Nd:YAG triangle slab laser pumped by 2D diode array. The pump beam
quality with respect to pump/mode overlap efficiency was investigated
theoretically and experimentally. Two cavity schemes with and without
forming optics were verified in free running and passively Q-switching
modes. Slope efficiency of 45% and output energy of 24 mJ for incident
60 mJ of pump energy were achieved in free running mode. Applying
crystal as passive Q-switch, the output energy of 5 mJ and 0.5 MW peak
power were obtained in the optimised resonator.
The paper presents investigation
results of optical, spectroscopic,
and generation parameters of YAG:Nd3+ with higher concentration ofNd3+
ions (1.1–1.8 at. % Nd3+). YAG:Nd3+ single crystals were
obtained by the
Czochralski method. Investigations on optical quality were carried out
using elastoscopic and interferometric methods. Absorption spectra
the spectral range of 200–3000 nm (Dl = I nm) and pumping
range of 750-850
nm (Dl = 0.1 nm) were determined. Also the spectra of luminescence
with radiation emitted by a laser diode of 808 nm were investigated and
lifetime of Nd3+ ions in the upper laser level (4F3/2) was determined.
In the all investigated crystals, doped up to 1.3 at.% Nd3+, the time
fluorescence decay from 4F3/2 level is 230 us. It was stated that high
level of Nd3+ ions doping (above 1.33 at. % Nd3+) causes reduction of
of the upper level 4F3/2 as a result of concentric quenching of
For the crystals of 1.8 at. % Nd3+ concentration, upper laser level
has been educed to 183 us. Also the results of generation
obtained in a laser system with the examined YAG:Nd3+ active media in
of side pumped "slabs" and inform of longitudinally pumped rod.
Plasma enhanced chemical vapour
deposition (PECVD) is
used in the deposition of various thin films such as amorphous silicon,
nitrides, oxides and diamond-like carbon. The authors succeeded in
of photovoltaic intrinsic a-Si:H with density of states of 1016
high photoconductivity gain. These films are the constituents of
p-i-n solar cells or heterojunction type with silicon-carbon window
of efficiency over 10%. The microwave plasma chemical vapour deposition
(MWCVD) seems to be a promising method for the deposition of