laser development for gravitational-wave interferometry in space
DESCRIPTION
Laser Development for Gravitational-Wave Interferometry in Space. Kenji Numata 1,2 , Jordan Camp 2 1 Department of Astronomy, University of Maryland, College Park, Maryland, 20742, USA 2 NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA. Outline. 1. Introduction - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/1.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Laser Development for Gravitational-Wave Interferometry in Space
Kenji Numata1,2, Jordan Camp2
1Department of Astronomy, University of Maryland, College Park, Maryland, 20742, USA
2NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
![Page 2: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/2.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Outline
o 1. Introduction– GSFC’s space laser history and recent trends
o 2. Master oscillator– Planar waveguide external cavity diode laser (PW-ECL)
o 3. Pre-amplifier– Low-risk component
o 4. Power amplifier– Noise and qualification tests
o 5. Summary
![Page 3: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/3.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
1. Introduction
o NASA/GSFC space laser history– Nd:YAG laser altimeters
o Recent activities and trends– Advanced laser altimeter (ICESat2, LIST, etc.)
• Yb fiber + Waveguide amp.– Gas sensing lidar (ASCENDS, etc.)
• Er fiber + Waveguide amp., stabilized seed laser• Parametric amplification
– Laser communication (LCRD, etc.)• Er fiber amp., telecom fiber components
– Interferometry (NGO/SGO, OpTIIX, etc.)
• Fiber & waveguide technologies wherever possible
MESSENGER/MLA - Mercury(2004-2012)Nd:YAG laser, >0.5B shots to date
LRO/LOLA - moon(2008-2012)Nd:YAG laser, 1+ Billion shots to date
ICESat/GLAS – Earth(2003-2010)Nd:YAG laser, 1.98 billion shots
MGS/MOLA - Mars(1996 -2000)Nd:YAG laser, 670 million shots
![Page 4: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/4.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Space laser for interferometry
o Master oscillator/fiber amplifier (MOFA) configuration– Both 1.0 µm and 1.5 µm
o Fiber/waveguide advantages– High robustness, high efficiency, small mass & size, easy cooling– Reliability data available (Telcordia) for many components– Reliable pump source at 97x ~ 980 nm for amplifier– New technologies become available
* Modulator, isolator, redundant LDs are not shown.
OpTIIX, GRACE-FO (1.54µm) NGO/SGO (1.06µm) MO+Preamplifier package
MO + Pre-amplifier Power amplifier
Master Oscillator
Pump LD(MM)
Gain fiber
Pump LD(SM)
Gain fiberWDM TFB~10mW ~100mW~2W
![Page 5: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/5.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
2. Master Oscillator
o Looking into various possibilities– Non-planar ring oscillator (NPRO)
• Best high-freq. noise performance. Legacy device.– Fiber laser
• Ring design (GSFC), DBR design (NP photonics)• Large relaxation oscillation
– Planar-waveguide external cavity laser (PW-ECL)• Semiconductor laser• Simplest, smallest, and most cost-effective• Best noise performance at low frequency
10-1
101
103
105
107
109
Freq
uenc
y no
ise
[Hz/
rtH
z]
10-4 10-2 100 102 104 106
Frequency [Hz]
Reference (master) laser
Stabilized Freerun
NGO requirement
K. Numata, 10.7452/lapl.201210034
DBR FL under thermal cycle test
Ring FL and its frequency noise performance NPRO and PW-ECL package comparison
![Page 6: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/6.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
PW-ECL features & status
o Features– Semiconductor gain chip + Planar lightwave circuit (PLC)
• Design details open to NASA– C-band (~1550nm), ~10mW output– Conversion to 1064nm underway
• Gain chip material change• Awarded SBIR contract to RIO for $750K (3/2012 ~ 9/2013)• NGO/SGO and other lidar applications
o Passed all space qualification tests– No performance degradation by
• Gamma, low/high energy proton, vacuum thermal cycling, pyro shock
0.40
0.30
0.20
0.10
0.00
-0.10Optic
al p
ower
chan
ge [d
B]
706050403020100
Dose [kRad]
20MeV 50MeV 50MeV (with shields)
12
10
8
6
4
2
0
Outp
ut p
ower
[mW
]
8006004002000
Number of cycles
40C -10C
Example result of high energy proton irradiation Example result vacuum thermal cycling
PLC
![Page 7: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/7.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
PW-ECL noise performance
o Relative intensity noise (RIN)– Smallest level among any lasers
• No relaxation oscillation peak around MHz range• Shot noise limited above ~100kHz
o Frequency noise– Phase lockable by injection current (100kHz UGF)– Frequency lockable to high finesse cavity and/or hyperfine molecular line
• NGO requirement level demonstrated by 13C2H2 molecule at 1542nm• Cavity stabilization facility under construction at UT Brownsville (V. Quetschke)
– GSFC funded 1/f noise reduction activity
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
Rel
ativ
e in
tens
ity n
oise
[/rt
Hz]
10-4 10-3 10-2 10-1 100 101 102 103 104 105 106
Frequency [Hz]
Shot noise
PW-ECL
NPRO
DBR fiber laser
Littman ECL
DFB LD
102103
104
105
106107
Freq
uenc
y Noi
se [H
z/rtH
z]0.0001 0.001 0.01 0.1 1 10 100 1000
Frequency [Hz]
Freerun Simplified setup Full setup NGO requirement
C. Clivati10.1109/TUFFC.2011.2121
Freerun RIN of various lasers
Freerun freq. noise of various lasers PW-ECL cavity locking PW-ECL molecular line locking
100
101
102
103
104
105
106
107
108
109
Freq
uenc
y no
ise
[Hz/
rtH
z]
10-4
10-3
10-2
10-1
100
101
102
103
104
105
Frequency [Hz]
PW-ECL
NPRO
DFB LD
DBR fiber laser
Littman ECL
![Page 8: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/8.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
3.Pre-amplifier
o Design– Single-clad Er- or Yb-doped fiber– Core pump by PM 97x-nm diode– Redundancy addition by polarization combiner
o Noise performance– No significant noise addition– Controllable after amplifier (demonstrated)
o Low risk component– Gamma radiation tests done on 1µm components– Simulation tools, many different vendors available
100
102
104
106
108
Freq
uenc
y no
ise
[Hz/
rtH
z]
10-4 10
-2 100 10
2 104
Frequency [Hz]
PW-ECL + EDFA After preamp Before preamp
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
Rel
ativ
e in
tens
ity n
oise
[/rt
Hz]
10-4 10
-2 100 10
2 104
Frequency [Hz]
PW-ECL + EDFA After preamp Before preamp
Frequency noise before/after pre-amplifier RIN before/after pre-amplifier
![Page 9: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/9.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Metrology interferometer for OpTIIX
o PW-ECL + preamp to be flown with OpTIIX – Optical Testbed and Integration on ISS eXperiment
• Technology demonstrator of ATLAST (~16m space telescope)– Spaceflight of PW-ECL + acetylene cell
• Planned launch: ~2015– Metrology system: heterodyne interferometer (S. Rao)– <1nm measurement error over hours
• Requirement achieved by simplified saturation setup• No external modulator, single pass
Simplified C2H2 locking setup with PW-ECL
Laser truss system concept
![Page 10: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/10.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
4.Power Amplifier
o Design– All fiber coupled (tapered fiber bundle)– Large mode area, double-clad Yb fiber– Forward pump to avoid risk and noise sources
• Catastrophic failure can occur with improper implementations
o Noise performance– No additional frequency noise– NGO requirement level
• Differential phase noise (@2GHz)• Stabilized low frequency RIN
10-6
10-5
10-4
10-3
10-2
10-1
Phas
e no
ise
[cyc
le/rt
Hz]
0.0001 0.001 0.01 0.1 1 10
Frequency [Hz]
Differential phase noise (1.4W output, Liekki fiber) NGO requirement
MM Pump LD Yb LMA DC fiber
TFB>1.4W
Redundant LD
Isolator Input mon. Output mon.90/10
coupler99/1
coupler
From seed>40mW
10-82
4
10-72
4
10-62
4
10-5
Rela
tive
inte
nsity
noi
se [/
rtHz]
103 104 105 106 107 108
Frequency [Hz]
After amplifier (stabilized) After amplifier (free-run) NPRO (seed) only Shot noise
10-5
10-4
10-3
10-2
10-1
Rela
tive
inte
nsity
noi
se [/
rtHz]
0.0001 0.001 0.01 0.1 1
Frequency [Hz]
After amplifier (stabilized) After amplfiier (freerun) Requirement (LISA)
Differential phase noise RIN and its stabilization (low/high frequency ends)
![Page 11: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/11.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Qualification tests on power amp.
o Packaging optimization for TFB– Screening by thermal imager– Proper packaging reduces temperature gradient
o Gamma irradiation on gain fiber– 200 Rads(Si)/min to a total dose of 60 kRads(Si)– Certain brand shows unrecoverable damage
• Probably due to dopants in the core– Sensitive but no showstopper
o Vacuum thermal cycling– Marginal power/PER degradation at ~1.5W level
60
50
40
30
20
10
0Tem
pera
ture
[C] /
PER
[dB]
131211109876543210
Time [hours]
2.0
1.5
1.0
0.5
0.0
Power [W]
Temperature (left axis) PER (left axis) Power (right axis)
2.0
1.6
1.2
0.8
0.4
0.0
Out
put p
ower
[W]
4.03.02.01.00.0
Pump power [W]
Nufern fiber Before gamma irradiation After gamma irradiation
2.0
1.6
1.2
0.8
0.4
0.0
Out
put p
ower
[W]
4.03.02.01.00.0
Pump power [W]
Liekki fiber Before gamma irradiation After gamma irradiation
Vacuum thermal cycling test Gamma on two different Yb fibers
![Page 12: Laser Development for Gravitational-Wave Interferometry in Space](https://reader035.vdocument.in/reader035/viewer/2022062815/56816937550346895de09b50/html5/thumbnails/12.jpg)
Goddard Space Flight Center 9th LISA Symposium, 23 May 2012Kenji Numata
Summary
o NASA/GSFC has been involved in space-borne laser since 90’s– Actively seeking innovative solutions to meet future science missions’ goals
• Fiber/waveguide technologies to space– In-house capability to build & test space lasers– Common requirements for all laser instruments
• Lifetime, reliability, and efficiency
o GSFC invested ~$1.2 M over 3 years on LISA laser development– Amplifier development and noise measurements– PW-ECL noise and reliability studies
o Expected to finish qualification of LISA laser by the end of FY13
– System test with 1064nm PW-ECL + pre-amp. + power amp. to be done– 1542nm PW-ECL + Er pre-amplifier to be flown to ISS– No showstopper found