Transcript No Slide Title - DCC

Status of LLO PSL
J. Kovalik, LIGO Livingston Observatory
LIGO-G010070-00-D
Lasers and Optics Working Group
March 15, 2001
1
Overview
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General Performance
Pre-Mode Cleaner
Intensity Noise
Frequency Noise
Future
LIGO-G010070-00-D
Lasers and Optics Working Group
2
General Performance of PSL
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Master Oscillator Power Amplifier (MOPA) in almost
continuous operation from 08/99-02/01
Laser output power slowly degraded over time
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Laser power decreased from 10W to 3W
NPRO pump power decreased from 500 mW to 50mW
NPRO noise performance degraded-frequency spikes and mode hopping
With NPRO replacement –current output ~6.75 W
Improvements made to Frequency Stabilization Servo
Improvements made to Pre-Mode Cleaner
Changes made to mirror mounts to reduce frequency noise
• Ongoing table configuration improvements
LIGO-G010070-00-D
Lasers and Optics Working Group
3
Pre-Mode Cleaner Changes
Old Pre-Mode Cleaner
New Pre-Mode Cleaner
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~65% Throughput
4.5 MHz bandwidth
Optically Cemented
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•
Hermetically sealed
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atmospheric pressure
180
18.6
140
Temperature
PZT Voltage
16
160
15
140
14
120
13
100
12
80
11
0
12
24
36
48
60
60
72
Temperature in degrees Celsius
PZT Voltage
PZT Voltage
Atmospheric Pressure (-1000) mbar
17
Higher body resonance
18.5
120
18.4
110
18.3
100
18.2
90
18.1
80
18.0
70
17.9
60
17.8
50
0
12
24
time in hours
LIGO-G010070-00-D
130
36
48
60
72
84
96
108 120
time in hours
Lasers and Optics Working Group
4
PZT Voltage
~75% Throughput
5.5 MHz bandwidth
Epoxied at discrete points
Open to atmosphere
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Intensity Noise
intensity noise in V/Hz
1/2
1E-4
shot noise
after PMC
before PMC
electronic noise
DC current of 48 mA
1E-5
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1E-6
Old Pre-Mode
Cleaner
Old Laser
1E-7
1E-8
0
2
4
6
8
10
Frequency in MHz
LIGO-G010070-00-D
Lasers and Optics Working Group
5
Frequency Noise
Frequency noise in Hz/Hz
1/2
free running laser
in loop measurement
mode cleaner as analyzer
10
1
0.1
0.01
100
1000
10000
100000
frequency in Hz
LIGO-G010070-00-D
Lasers and Optics Working Group
6
Mirror Mounts
New Focus Centre
840 Hz ???
Fixed Periscope
610 Hz
LIGO-G010070-00-D
New Focus Corner
840 Hz ???
Fixed “Sovietski”
1.4 kHz
Newport Ultima 100 (“open”) Opto Sigma Ultra Stable
with 1” post -580 Hz
400 Hz
Ultima 100
with pyramid base
590 Hz
Ultima AC (“closed”)
with pyramid base
850Hz
Lasers and Optics Working Group
Micro Controle
730 Hz
7
Future
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Intensity Stabilization (ISS) must still be implemented
Tidal servo must still be implemented
New table layout
Study acoustic environment
LIGO-G010070-00-D
Lasers and Optics Working Group
8