Compact, High‐Energy, Mid‐Infrared  Pulsed Parametric Source for High‐ Resolution Gas Sensing and Ablation

Mr. Trent Berg, Nathan Greenfield, Aaron Anderson, Christopher Wilson, Eric  Seger, David Kozicki, Randy Reibel and Dr. Pete Roos For info contact:

Dr. Pete Roos [email protected]

Presented by: Dr. Randy Reibel

Bridger Photonics • Core technologies – Precision LADAR • Highest resolution distance measurements in the world

– Precision LIDAR • Only compact high-energy affordable mid-infrared laser

– Advanced Imaging • SAL • 3D Imaging

• Performance – Rapid growth • Under 4 years of operation • 2 → 17+ employees • $110k → >$3M (2011) annual revenues

Precision LADAR • Innovation – Highest resolution distance measurements in the world – Can measure multiple surfaces over short and long distances – Incredibly sensitive coherent detection

• Markets – Industrial Metrology (short range) • Precision measurement applications • OEM insertion for large scale customers

– LADAR (long range) • Target detection and identification applications • Military customers

See Dr. Zeb Barber’s talk tomorrow for latest metrology results…

Precision LIDAR • Innovation – High-energy affordable mid-infrared pulsed laser – Broadband version for ablation – Narrowband version will enable hand-held gas sensing

• Markets – Laser Ablation • Mass spec and materials processing applications • OEM followed by direct sales • Estimated $4M to $10M / yr

– Gas Sensing • CO2 and meth lab sensing • Mostly public sector customers • Estimated $1M to $3M / yr

Advanced Imaging • Innovations – – – –

Highest resolution and most sensitive 3D imager Advanced compressive sensing capabilities for target identification Synthetic aperture ladar MEMS focus control / scanners for imaging gas plumes and 3D imaging

Next Generation Laser Scanner / Trackers

Optical Zoom

0.9 cm 0.9 cm

1.0 cm 1.0 cm

Membrane Membrane

Electrodes Electrodes

Motivation Our criteria for selecting the laser to develop…

Motivation – Gas Sensing • Methamphetamine (Meth) Manufacturing – Considered most addictive illicit drug – Use remote sensing to uncover labs – Provide evidence to secure search warrants

• Carbon Dioxide – – – –

Now a pollutant under fed Clean Air Act Emerging importance for climate change Carbon sequestration monitoring LIDAR for range resolved concentrations

• Other Gases

Effluents

– NASA atmospheric monitoring – Chemical weapons detection

• Handheld or UAV Mounted – Believe strongly that gas sensing within the next five years will transition to much closer ranges

Receiver Pulsed Transmitter

Gas Sensing from 2-5 microns • Advantages – Strong absorptions for most species of interest • Often 100 times stronger than near-IR overtones and combination bands

– Good atmospheric windows for long range sensing • ~2-2.5 microns and ~3-5 microns

– Lower molecular & aerosol scattering • Can penetrate adverse atmospheric conditions

• Disadvantages • But improving • Extended InGaAs

Transmission

– Poorer detector performance

1.0 0.8 0.6 0.4 0.2

– Immature laser sources

0.0

• Also improving

0.9

– Lower molecular & aerosol backscatter • LIDAR more difficult

Atmospheric CO2 Transmission – 100 meter path length

1 1.0

2

3

4

0.8 0.7 0.6

2.00

2.01

2.02

Wavelength (microns)

2.03

5

Possible Laser Sources • DFB Diode Lasers – Good coverage up to, but not beyond 3 microns – Reliable, proven, inexpensive but relatively low power – Multiple lasers could enable broad coverage

• Rare-Earth-Ion-Doped Solid State – Powerful, but limited spectral coverage and tunability – Expensive, typically not portable – Q-Switch is slow (pulse durations of ~100ns)

• Quantum Cascade – – – – –

Good coverage down to about 4 microns Becoming mature (but not there yet…) Significant heat generation problems Multiple lasers could enable broad coverage Relatively low power

Our Chosen Laser Source • Optical Parametric Generation – Allows easy coverage from ~1.4 microns to at least ~5 microns with one pump source – Can be seeded for narrow linewidth – Mature, reliable pump and conversion technology

• Pulsed Operation – Can achieve large pulse energies and peak powers – Short pulses useful for ranging – Large energies useful for single pulse detection (e.g. for moving platforms) – Average power applications will be dominated by CW QC lasers and DFBs

• Traditional Drawbacks – Large – Expensive – Inefficient

Photon Energy Conserved

Pump

Signal Idler

Traditional size conception of mJ level optical parametric oscillator

Key Components and Performance

Pump Source Development • In-House Pump Source – – – –

1064 nm passively q-switched Nd:YAG Diode pumped Consistently M210 mJ – Pulse energy stability ~ 0.5%

1 Hour Operation Std Dev 84 J

Parametric Generation • Single-pass OPG – Demonstrated > 1 mJ signal and idler output energy from PPLN, PPKTP, PPSLT – Demonstrated >35% total energy (signal + idler) efficiency – Challenge to avoid crystal damage – Challenge to avoid non-collinear phase matched effects (power clamps) 35 mm PPCLN crystal

Signal Output Energy (mJ)

2.5

y = 0.28*x - 0.22

2 1.5 1 0.5 0 0

2

4 6 8 Pump Energy (mJ)

10

Performance Summary • Pulse Energy – Achieved > 1 mJ for all tested wavelengths

• Pulse Duration – < 10 ns

• Pulse Repetition Rate – Achieved 20 Hz – 100 Hz should be possible

• Spatial Mode – Achieved M2 < 2 – Demonstrated