Method and apparatus for fast laser pulse detection using gaseous plasmas

Patent · Sun Jan 01 00:00:00 EST 1984

OSTI ID:864987

McLellan, Edward J ^[1]; Webb, John A ^[2]

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1. Los Alamos, NM
2. Albuquerque, NM

The method and device of the instant invention is a detector of pulsed laser radiation which utilizes the electromotive force generated by the plasma formed when such radiation is focused onto a surface (1). Measurements are made with a 10.6 .mu.m CO.sub.2 laser capable of producing peak intensities of 10.sup.13 W/cm.sup.2 when directed through a converging lens (2). Evacuated detector response to such laser intensity is 1 kV signal peak amplitude and subnanosecond risetimes into a 50.OMEGA. load (3). Detector performance is found to be greatly altered with the introduction of a background gas (4). For example, with one atmosphere of air, the detector produces prompt signals of the order of 1 V with subnanosecond response for pulse trains lasting 100 ns. With argon, krypton, or zenon at pressures of the order of 10 torr, the detector generates "trigger pulses" of about 250 V amplitude and 0.2 ns risetimes. Such detectors are quite robust when irradiated with high intensity laser radiation and are useful for qualitative laser beam monitoring.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• Assignee: United States of America as represented by Department of Energy (Washington, DC)
• Patent Number(s): US 4447151
• OSTI ID: 864987
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
fast
laser
pulse
detection
gaseous
plasmas
device
instant
detector
pulsed
radiation
utilizes
electromotive
force
generated
plasma
formed
focused
surface
measurements
10
capable
producing
peak
intensities
13
cm
directed
converging
lens
evacuated
response
intensity
kv
signal
amplitude
subnanosecond
risetimes
50
omega
load
performance
found
greatly
altered
introduction
background
gas
example
atmosphere
air
produces
prompt
signals
trains
lasting
100
argon
krypton
zenon
pressures
torr
generates
trigger
pulses
250
detectors
robust
irradiated
useful
qualitative
beam
monitoring
beam monitoring
trigger pulse
pulse detection
pulse train
laser pulse
laser beam
pulsed laser
laser radiation
plasma formed
pulse trains
peak amplitude
converging lens
intensity laser
laser capable
detector performance
trigger pulses
electromotive force
gaseous plasma
motive force
signal peak
beam monitor
/356/136/250/313/