Solid State and Nonlinear Optics Sources - Q-Peak

Solid State Lasers and Nonlinear Optics Sourcesfor Remote Sensing and Imaging: Past, Present and Future

OSA Topical MeetingApplications of Lasers for Sensing and Free Space

Communications

San Diego, CAFebruary 3, 2010

Paper LSWE3

Kevin WallQ-Peak, Inc.

Outline

• Sources for lidar– Aerosol– DIAL– Wind-sensing

• Source for ladar– Ranging– 3-D imaging

• Future technologies– Hybrid (fiber-bulk) lasers– QCL-seeded OPOs

Contributions from: Glen Rines, John Flint, Yelena Isyanova, Alex Dergachev, Kevin Wall and Peter Moulton

High-energy KTP OPO allows generation of “eyesafe” pulsed power for aerosol sensing

KTP OPO

InputMirror

OutputMirror

Q-switched Nd:YLF1053 nm, 0-240 mJ,

10 ns, 10-50 Hz- or -

625 mJ, 30 Hz

Q-switched Nd:YAGOsc / Amp

1064 nm, 0-1.1 J,10 ns, 10 Hz

-or-

Telescope

OPOSignalOutput

0

100

200

300

400

500

1571

-nm

OP

O O

utpu

t

0.2 0.4 0.6 0.8 1 1.2 1064-nm Pump Energy (J)

4.5 W average power

Highest-energy, ns-OPOever?

Compact, ruggedizedlamp-pumped laser (CLH) with internal OPO

System Specifications

Output wavelength 1550 nmPulse length < 10 nsOutput power > 7.2 WattsRepetition rate 0 to 50 HzTelescope aperture 10"Telescope focal length f/10Field-of-View 0.5 mradBandpass filter width 3 nmDetector efficiency 0.7Total weight < 300 lbs

Compact Field-Deployable Lidar System built at Los Alamos used Q-Peak CLH OPO system

Application of CLEAR lidar to urban areas

Army biological standoff detection system(LR-BSDS) used Q-Peak high-power OPO

Development of large-aperture KTA crystals enables OPO operation at high average powers

3000 3200 3400 3600 3800 40000

20

40

60

80

100T = 75% @ 3297nm

T = 23% @ 3297nm

KTA 2cm KTP 2cm

Wavelength (nm)

%T

Absorption of the idler (3297 nm) energy in KTP crystals causes unacceptable crystal heating at high OPO pulse rates. KTA crystals do not absorb the idler, and allow operation at virtually unlimited average powers.

0 20 40 60 80 100 1200

5

10

15

20

25

30

35

Pump Power (Watts)Si

gnal

Pow

er (W

atts

)

M.S. Webb et al. Opt.Lett. 23, 1161 (1998)

Detail of LR-BSDS system mounted in UH-60

Use of a 7” diameter transmit telescope allows eyesafe operation at the aperture,even with system having a 30-W average-power transmitter

Outline




Laser-pumped, high-energy, ns Ti:sapphire laser

Developed with NASA Langley, DARPA support, 1986-1992

Pump #1

Pump #2

Output

GRM

HR

Ti:sapphirecrystals

Prisms

0

50

100

150

200

250

300

350

400

450

500

0 200 400 600 800 1000 1200 1400

Green pump energy (mJ)

Ti:s

apph

ire

outp

ut e

nerg

y (m

J)

790 nm727 nm911 nm960 nm

10-20-ns pulse duration

diffraction-limited

LASE system with Ti:sapphire laser has measured global water-vapor profiles

•The seed source is a single-frequency diode laser operating around 815 nm

•The pump laser produces two pulses spaced less than a msec apart, to provide on-line, off-line data for a “frozen” atmosphere

•LASE has flown > 30 times on an ER-2 and on a P-3 aircraft since 1995. Now being adapted for DC-8

Harmonic conversion of Ti:sapphirelasers for species sensing

700 750 800 850 900 950Wavelength (nm)

NO2

Benzene

Hg

Toluene Ozone

NO

SO2

Cl2

2nd

3rd

4th

Harmonic

Performance of third-harmonic converterto 300-nm region for ozone (NASA funded)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

0 20 40 60 80 100

Input Energy (mJ)

THG

Out

put E

nerg

y (m

J)

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

Effic

ienc

y (%

)

Output - unseeded

Output - seeded

Efficiency - unseeded

Efficiency - seeded

Facility for Airborne Atmospheric Measurements (FAAM) (UK)

BAE 146-301 Large Atmospheric Research Aircraft

G-LUXE

Detailed block diagram of FAAM lidar sourcefor ozone and water-vapor DIAL

Pulsed Ti:sapphireLaser

HarmonicGeneration

Ramp /LockElectronics

Pump LaserLamp Drivers

LasersCooling

WavemeterWavemeterComputer

NIROutput942-942

nm

Optical bench

Electronics rackElectrical CoolantOptical

ECDLSEED

ECDLSEED

ECDLSEED

ECDLSEED

ECDLSEED

Switch

Seed LaserControl/Drive

MasterControl

CLHPump Laser

UVOutput297-319

nm

25-Hz pulse rate, 5 pulses each a new wavelength, repeat

Final box design for FAAM lidar

High-energy, 1-kHz, diode-pumped Nd:YLF MOPA (driver for OPO-based ozone DIAL system)

30-W Fiber-coupleddiode laser

Single-frequency,passively Q-switchedNd:YLF Oscillator,

1 mJ

Double Isolator

Pre-amplifier 15 mJ

Pre-amplifier 215 mJ

W/2x60 W diodes

Finalamplifier

55 mJ

W / 285 W nLight Cascade Laser

W/2x40 W diodes

Pre-amplifier 324 mJ

W/2x90 W diodes

h Quasi-CW pumping

h 1 kHz pulse rate

h 500-μsec pump pulses

h 50% duty cycle

hEnd- & side-pumping

hSimple relay-imaging

hSingle frequency

h10-nsec pulses

h55 mJ per pulse

Outline




SALTS 2-micron coherent lidar sourcebuilt for Lockheed for wind profiling off ships

FIBER-COUPLED15 WATT

LASER DIODE

OUTPUT

COLLIMATING LENS

LENS

PUMPFOCUSING

M3

LASER CRYSTAL

BIFURCATEDFIBER

TE COOLER

M2

AO Q-SWITCH

M1 M4

1-W single-frequencyunidirectional ring

4 mJ, 1 kHz PRR single-frequency source at349 nm for incoherent-detection wind-sensing

4

11

11

2

5

3

79

8

10

11

1

12

12

1

13, 14

Amplifier Gain Modulew/ 90-W Lightstone diodes

NCPM LBO(SHG) crystal

15 CPM LBO(THG) crystal

17

16

1047-nmoutput

349-nmoutput

Beamdump

SLM

Seed

Lase

r

Seeder ElectronicsPhotodetector

Optical Isolator

Oscillator Gain Modulew/ 40-W diodes

UV-ContollerPhotodetector

6

G-5398

Outline




SLR2000 transmitter for precision satellite ranging based on amplified microchip

Fiber

Nd:YAG/Cr:YAG Microlaser

TelescopeIsolatorλ/2 plate

Cylindrical lens

HR Mirror

Nd:YVO4 Multipass Amplifier

λ/2 plate

SHG

Diode laser

532-nmbeam

Design: MPV-amplified microchip laserPulse duration: 200-300 psPulse energy: 200 uJ at 532 nmPulse rate: 2 kHz

Photograph of hardwaredesigned for remote, autonomous operation

MPS short-pulse technology, 1 kHz rate, for satellite-ground ranging

Fiberbundle

Nd:YLFcrystal

Imagingtelescope

Laserdiode

Lens Outputcoupler

HR/HTcoating

AR coating

λ/2 plate

Cylindricallens

HR MirrorNd:YLF Amplifier

Isolator

Sphericallens

Nd:YLF Laser

1047-nm output

Short-pulse Nd:YLF

laser(1.5 mJ, 7.5 ns)

Complete system

(10.5 mJ,1 kHz)

Q-switch

Outline




Nd:YVO4 laser head and pump assembly design for autonomous munitions testing

Laser Head

RF

Optical Fiber

Temperature Controller

Micro-Controller

Diode-Laser Current Source

Q-Switch Driver

28 V

28 V

28 V

Current Set Current

Sense

RS-232

Temp. Set

Temp. Sense

28 V

RF Control

0-40 Amp.

Diode Laser

TE Coolers

0-28 V

Diode Temp.

Ext. Trigger

Output Coupler

Q-Switch

Laser Crystal

Semi-Tactical Pump Assembly 10 W @ 1 μm

Schematic of system10-W average power30-100 kHz6-10 ns pulsesTEMoo

Photograph of systemflown in helicopters and jet aircraftUsed 2-D scanner, range sensingto build 3-D image

Ruggedized laser for advanced ladar

Laser head:Nd:YLF 1047 nm30 W Pave, TEMoo3-9 kHz, 8-15 ns pulses

Used linear array, vehiclemotion to build 3-D image

Power supplyDC-DC converterRS-232 controlled

Transmitter for LANL RULLI System

OSC FCL

MPV

SHG

ISO

ROT

HR

HR

HR

HR

DM

DM Output

HR

PBS

BD

λ/2

λ/2

System stage Parameter Value Wavelength 1064 nm Linewidth < 0.1 nm Beam quality TEM00 Osc diode current: 1.0-2.0 A Nominal

2.5 A Maximum Pulsewidth ~0.9 ns Repetition rate range 20-200 kHz Nominal

Master Oscillator:

Power 0.52 W Nominal Amp diode current: 30 A Nominal

34 A Maximum Amplifier:

Power (2-pass) 10 W Nominal 12 W Maximum

Wavelength 532 nm Pulsewidth ~0.8 ns

SHG:

Power 5.0 W Nominal 7.5W Maximum

Outline




Motivation for hybrid system

• Development of a 2050-nm laser source:– High-energy (> 200 mJ)– High repetition rate (200-1000 Hz) – High beam quality (TEM00)

Ho:YLFOSC

Tm:fiberlaser

>200 mJ2050 nm

200 Hz - 1000 Hz• Immediate applications:

• Pump source for OPOs (IR DIAL and long-path sensing)• Long-range 2D and 3D imaging, coherent systems for

Doppler and vibrometry sensing

CW1940 nm

Ho:YLFAMPs

2050-nm Ho:YLF MOPA

Ho-stage/ Regime CW 100 Hz 500 Hz

Osc/Amp #1 39 W 55 mJ 50 mJ

Amp#2 76 W 110 mJ 95 mJ

Amp#3 115 W 170 mJ 140 mJ

Tm-pump #1~120 W at 1940 nm

Osc/ Amp #1

Amp #2

Amp #3



Tm-fiber laser TLR-100-1940 IPG Photonicswww.ipgphotonics.com

Operation regime CWBeam Profile TEMooOutput power ≥ 120 WWavelength 1940 nmPolarization RandomLinewidth ≤ 2 nm

> 1 kW of power output at 2045 nm from Tm:fiber laser

0

200

400

600

800

1000

1200

0 500 1000 1500 2000

Pump Power (W)

Sign

al P

ower

(W)

53.2% slope

Outline




MWIR OPOs – nanosecond pulse, high beam quality

2

3

4

5

6

7

8

9

51 52 53 54 55 56 57 58

Angle (degrees)

Sign

al, i

dler

wav

elen

gths

(um

)

Ho-MOPA

RistraOPO

DM1

DM2

DM4

DM3

BS

OPA output

Ch. 1<60 mJ

OPA

HR

HR

ZGP 10 mm

ZGP 10 mm

Ho-MOPA

RistraOPO

DM1

DM2

DM4

DM3

BS

OPA output

Ch. 1<60 mJ

OPA

HR

HR

ZGP 10 mm

ZGP 10 mm

0

5

10

15

20

25

30

35

0 20 40 60 80 100 120

Ho-pump energy (mJ)

OP

A ou

tput

(mJ)

100 Hz300 Hz500 Hz

Signal seed ~10 mJ

Signal seed ~9 mJ

Signal seed ~9 mJ

Tuning curve of ZGP OPO pump at 2050 nmcovers entire MWIR band

RISTRA OPO (with Sandia collaboration)provides high beam quality

OPO-OPA design produces high energy

10-W average power, 3400 nm at 500 Hz

Quantum-cascade-laser (QCL) seed provideswavelength control and narrow linewidth

MIROPO

QCLseeder

2050-nmpump laser

2.2 to 4.0 umsignal output

4.0 to 22 umidler output

Design goal:200 mJ/pulse>50-Hz PRRpump laser

Photograph ofZGP OPO demonstration

Summary

• Solid state lasers (fixed wavelength or tunable) combined with nonlinear optics provide:– Conversion of non-eyesafe to eyesafe wavelengths, for

aerosol detection– Power tunable to absorption lines of atmospheric species, for

DIAL systems– Short-pulses at high rates for range-and 3-D imaging– Single-frequency, narrow-linewidth power for wind and

vibration sensing• Emergence of diode-pumping technology favors use of higher

pulse rates and lower pulse energies, if averaging is possible• Hybrid (fiber-bulk) systems combine high efficiency of cw fiber

lasers with high pulse energies of bulk materials• QCLs (and variants) combined with OPOs provide a new, narrow-

linewidth, high-peak-power source for DIAL and other sensing

Solid State and Nonlinear Optics Sources - Q-Peak

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