13th International Laser Ranging
Workshop
"Toward Millimeter Accuracy"
Submitted
Abstracts
Laser Technology Development (K. Hamal and Howard Donovan, for Y. Gao)
Title |
Primary Author |
Kilohertz Laser Ranging at Graz |
Georg Kirchner |
Austrian Academy of Sciences
Observatory Lustbuehel
Lustbuehelstrasse 46
A-8042 Graz
AUSTRIA
Voice: +43-316-873-4651
Fax: +43-316-873-4641
Email: kirchner@flubpc04.tu-graz.ac.at
Franz Koidl
Austrian Academy of Sciences
Observatory Lustbuehel
Lustbuehelstrasse 46
A-8042 Graz
AUSTRIA
At present, SLR Graz is ranging to all satellites with a standard
Nd:YAG Laser, with 10 Hz repetition rate, using SemiTrain pulses
with a total energy of about 30 mJ per shot and a pulse length
of 35 ps; we intend to replace this 20 years old system with a
diode pumped, solid state laser, operating with 1 kHz repetition
rate nominally (10 Hz to 2 kHz specified), with single pulse energy
of 0.5 mJ per shot at 532 nm, and a pulse length of 10 ps.
While the present laser system will remain operational for special
experiments like MultiColor Ranging etc., the expected advantages
of the new laser system are up to kHz return rates for all low
satellites, significantly improved return rates from LAGEOS, and
same return rates from high orbiting satellites as now; this should
map into much better defined Normal Points for all satellites
up to and including LAGEOS.
Most requirements to implement such a laser system into the SLR
station have been built or installed already during the last years:
The Graz Event Timer (E.T.) - operational since autumn 2000 -
already allows repetition rates of up to 2.5 kHz; a new Range
Gate Generator has been designed and built in Graz to allow kHz
repetition rates, while defining the Range Gate with 500 ps resolution.
The necessary budget for this project has been applied for, but
we are still waiting for a final decision.
Oral paper; received August 9, 2002
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Mechanical measurement of laser pulse duration |
Jean-Louis Oneto |
OCA/CERGA
Avenue Copernic
06130 Grasse
FRANCE
Voice: +33.4.93.40.53.80
Fax: +33.4.93.40.53.33
Email: oneto@obs-azur.fr
Jean Gaignebet
OCA/CERGA
Avenue Copernic
06130 Grasse
FRANCE
An original interferometric device has been developped, which
allows to measure the duration of laser pulses in the picosecond
domain, with a precision of few percent. This could be a cheap
and convenient alternative to the streak-camera methods available
today.
Oral paper; received August 22, 2002
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Lasers for Multiwavelength Satellite Laser Ranging |
Karel Hamal |
Czech Technical University
Brehova 7
115 19 Prague 1
CZECH REPUBLIC
Voice: +420 2 21912246
Fax: +420 2 21912252
Email: prochazk@mbox.cesnet.cz
I. Prochazka, J. Blazej
Czech Technical University
Brehova 7
115 19 Prague 1
CZECH REPUBLIC
Yang Fumin, Hu Jingfu
Shanghai Observatory
CHINA
Jean Gaignebet
Grasse
FRANCE
To find the right laser for multiple wavelength millimeter SLR
one can consider he NdYAG / SHG / THG, NdYAG / SHG / Raman in
Hydrogene/1S/1aS and the Titanium Sapphire fundamental / SHG at
different repetition rates. Our optimization of the four wavelengths
Raman laser at 1.064, 0.53, 0.68 and 0.45 um gives 60, 20, 7,
2 mJ at 20Hz for 35 psec pulses. The laser setup, conversion efficiencies
and the far field beam structure will be displayed. The laser
is dedicated for the new Shanghai SLR station.
Oral paper; received August 22, 2002
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High-Power, Short-Pulse Microlaser - Power Amplifier
System |
Yelena Isyanova |
Q-Peak, Inc.
135 South Road
Bedford, MA 01730
USA
Email: isyanova@qpeak.com.
Kevin F. Wall, John H. Flint and Peter F. MoultonQ-Peak, Inc.
135 South Road
Bedford, MA 01730
USA
John Degnan
NASA Goddard Space Flight Center
Code 920.3
Greenbelt, MD 20771
USA
Presented by Peter Moulton
Passively Q-switched Nd:YAG/Cr:YAG microlasers are simple, compact
and reliable sources of high repetition rate (100 Hz to 20kHz),
near-infrared, sub-nanosecond pulses. To date, low-energy (1 to
10 mJ/pulse) and mid-energy (10 to 50 mJ/pulse) microlasers are
commercially available with pulse durations of 600 to 1000 ps.
For some applications, for instance, high precision ranging and
imaging, higher-energy pulses, as much as 500 mJ/pulse, are required
with pulse durations approaching 200 ps. In this work, we report
on a prototype of a Laser Transmitter (LT) for the NASA SLR2000
system, generating 335 mJ at 1064 nm with efficient (60%) harmonic
conversion to the visible and pulse durations below 400 ps. The
LT is based on the use of a MOPA design with a microlaser oscillator
and multipass Nd:YVO4 amplifier. In recent work we have achieved
15-mJ pulses at 1.06 mm from our microlaser, with pulse durations
in the green as short as 270 ps.
Oral paper; received September 19, 2002
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