Security Applications Using Broadly TunableSecurity Applications Using Broadly TunableExternal Cavity Quantum Cascade Lasers for 

the Mid‐IR (EC‐QCL)the Mid IR (EC QCL)

Timothy Day, David Arnone, Miles J. Weida, Michael Pushkarsky, Dave Caffey, 

Vince Cook, Chris Armacost,

Daylight Solutions, Inc.www.daylightsolutions.comwww.daylightsolutions.com

Outline

• Applications in Molecular Detection

• External Cavity Review and Recent Tuning ResultsExternal Cavity Review and Recent Tuning Results

• Molecular Detection and Recent Performance

• Mid‐IR Illumination and Recent Performance

• SummarySummary

Pl tf P tf liDate ProductJune 06 Broadly tunable mid‐IR

Date ProductMar 09 High power multi‐band 

Platform Portfolio

June 06 Broadly tunable mid IR laser systems for 

scientific applications

Mar 07 High sensitivity, low noise mid‐IR 

Mar 09 g po e u t ba dlaser systems (limited 

release)

Oct 09 Size, weight reduction, environmentally

detector/receiver

June 07 Battery operated illuminator for 

commercial & military 

environmentallyruggedized packaging

Mar 10 Added capabilities,platform‐specific packaging, systemy

applications

Sept 07 Broadly tunable, MHF laser systems for 

Scientific Applications

packaging, system integration

Ruggedized fiber cable LRU

Mar 10 Ultra‐broadly tunablepp

Dec 07 “Swept Sensor,” portable OEM sensors for molecular detection

O t 08 Fi ed a elength c

Mar 10 Ultra broadly tunable mid‐IR laser systems

(> 300 cm‐1)

Jan 11 High Powered,Air CooledOct 08 Fixed wavelength cw

and pulsed illuminators for OEM applications

Air Cooled,Fixed WavelengthLaser Systems

Molec lar DetectionGlucose

Monitoring

Molecular Detection

Medical Breath DiagnosticsHigh Speed, Portable, Swept

Sensor™ Systems

H it l A th iHospital Anesthesia Monitoring

Imaging Spectroscopy

Infrared Imaging

Pl tf t h l tili d

Scientific Instrumentation

Imaging Spectroscopy

Breath Alcohol Detection

Platform technology utilized in multiple applications Environmental Monitoring

Networks

Why Mid‐IR?

DefenseDefense

Daylight Solutions tunable External Cavity Laser coverage

Common Explosives & CWA Agents

The Source for all Applications in the Mid-IR

Narrow tuning reveals

Why is Broad Tunability Important?Narrow tuning reveals only a snapshot.

Laser scan

Lasers Technical Seminar, Lahat Technologies Ltd.

The Source for all Applications in the Mid-IR

d b l

so you can seeLaser scan Broad tunability reveals

Broad Tunability

…so you can see the whole picture!!!

Broad tunability reveals the entire fingerprint…

Lasers Technical Seminar, Lahat Technologies Ltd.

Why is Broad Tunability Important?Composite spectrum Deconvolved spectrum

H2OEthanol

Daylight Solutions broad tuning >250 cm-1

Daylight Solutions broad tuning >250 cm-1

ce e H2O

CO2

Ethanol

Abso

rban

c

Abso

rban

ce

950 1000 1050 1100 1150 1200Wavenumber (cm-1)

950 1000 1050 1100 1150 1200Wavenumber (cm-1)

• “Fingerprint” analysis yields multi-species detection with single laser• High degree of selectivity from background interference• Pattern recognition algorithms and embedded DSP can determine specific

constituents and concentrations

External Cavity QCL Review and Recent Tuning ResultsTuning Results

Sub‐threshold GainCO2

> 700 cm‐1

B d i t b d t id bl li ht4 µm 5 µm

• Broad gain must be managed to provide usable light– Distributed Feedback (DFB) QCLs

• Sacrifice gain and yieldQCL d ’ f i SLD– QCLs don’t function as SLDs

– External Cavity Laser

Coherence Collapse• Bandwidth as function of drive current for mirror feedback

– No easy predictor of bandwidth behavior– Need external control of bandwidth

850 mA

rren

tea

sing

Cur

920 mA30 cm‐1

Incr

e

920 mA

4.0 µm

External Cavity quantum cascade Laser (ECqcL™)

• Grating feedback narrows output• Grating feedback narrows output • Rotation of grating accesses gain bandwidth

US Patent # 7,424,042, 7,466,734, 7,492,806, 7,535,656, 7,535,936, & 7,796,341

Broadening QCL Gain

CW Tuning Ranges (Average power)

Pulsed Tuning Ranges g g(Peak. power)

Beam Characteristics• Beam Divergence - < 5 mrad

P l i ti Li 100 1• Polarization - Linear 100:1• Beam Quality - TEM00• Pointing Stability - < 1 mrad for Tunable, < 0.1 mrad for Fixed

Beam Profile — M2 Typical 1.3

Current QCL Capabilities – Tuning Range

External Cavity QCL Tuning Range

• Tuning range for single lasers continues to increaseFaist J et al Science 264 pg 553 (1994) Maulini R et al Appl Phys Lett 88 (20) pg201113 (2006)Faist, J., et al., Science, 264, pg. 553 (1994)Luo, G.P. et al., Appl. Phy. Lett. 78, pg 2834 (2001)Gmachl, C., et al. IEEE J. Quant. Elec., 38(6) pg 569 (2002)Maulini, R., et al. Appl. Phys. Lett., 84 (10), pg. 1659 (2004)

Maulini, R., et al., Appl. Phys. Lett., 88 (20), pg201113 (2006)Wittmann, A., et al., IEEE J. Quant. Elec., 44 (11), pg. 1083 (2008)Hugi, A., et al., Appl. Phy. Lett., 95, pg. 061103 (2009)

Molecular Detection Applications and Recent PerformancePerformance

Accessing 3.x µm

• Type I GaSb diodes incorporated in external cavities for access to “short” wavelengthscavities for access to “short” wavelengths

500 cm‐1

2.86 µm 3.33 µm

Ridge Waveguide Laser Diode Sub-threshold gain

ECDL Tuning Performance

6

Pulsed Tuning Performance • Pulsed and cw operation at 3 15

2

3

4

5

Pow

er(m

W)

500 mA

400 mA Access to acetylene and methane C H stretch

3.15 µm

CW Tuning Curve

0

1

3070317032703370

Wavenumber (cm-1)

375 mA methane C‐H stretch absorption spectra (PNNL simulations)

4

5

6

(mW

)

CW Tuning Curve• cw tuning

• 2.93-3.26 µm • 345 cm-1 of tuning (11%

0

1

2

3

Powe

r ( 500 mA400 mA300 mA

345 cm of tuning (11% of center wavelength)

• Next generation at 3.25 um3070317032703370

Wavenumber (cm-1) and reached 9 mW CW

Extremely sensitive detection of NO2 employing off-axis integrated cavity output spectroscopy coupled with multiple-line integrated absorption spectroscopy

Data processing and analysis:• frequency modulated spectroscopy techniques to i th i l t i tiimprove the signal-to-noise ratio • multiple-line integrated absorption spectroscopy to improve the sensitivity of p ydetection.

Enables detection of trace amounts of explosive compounds

- Rao* and Karpf – Adelphi University

Trace concentrations of NO2 with ahigh sensitivity of the order of 28 ppt

This spectrum was used to select a region with a dense NO2spectrum that was free from interference due to water lines. The region used for the reported work (between 1655:3cm−1 and1657:3cm−1) is highlighted in the1657:3cm 1) is highlighted in the chart with a white background.

Distributed nerve gases sensor based on IR absorption in hollow optical fiber – CREO & Selex Sistemi Integrati

Concept design of the line-sensor

Laser drilling micro holes

Layout illustrating a cross section of the cell f i t f i th HCF ith th IRfor interfacing the HCF with the IR source/detector and the air sampling circuit.

Distributed nerve gases sensor continued…

Comparison between the IR absorption spectrum of ethyl alcohol, as obtained by integrating 14 spectral scans, and

Grid of line-sensors indoor applications

the corresponding IR spectrum retrieved from the PNNL database.

Quantum Cascade Laser‐Based Photoacoustic Spectroscopy for Trace Vapor Detection and Molecular Discrimination

• US Army Research Labs: Ellen Holthoff 1,John Bender 1, Paul Pellegrino 1

Quantum Cascade Laser‐Based Photoacoustic Spectroscopy for Trace Vapor Detection and Molecular Discrimination

• US Army Research Labs: Ellen Holthoff 1,*, John Bender 1, Paul Pellegrino 1

Mid‐IR Illumination Applications and Recent PerformancePerformance

Standoff Detection of Explosives with EC‐QCLFrank Fuchs - Fraunhofer-Institut

The sensor head comprises the tunable external quantum cascade cavity laser,an IR imager, and a visible camera. The system

ft bl t ti id tifi tisoftware enables automatic identification.

Pump–probe Photothermal Spectroscopy EC-QCL

R H Farahi1, A Passian1,2, L Tetard1R H Farahi , A Passian , L Tetardand T Thundat3

1 Oak Ridge National Laboratory2 University of Tennessee3 University of Alberta

Pump–probe standoff HSI using QCL-based photothermal

3 University of Alberta

QCL-based photothermalspectroscopy of a target surface:

• QCL pump thermo-optically stimulates the surface •The minimally invasive probe beam (red) same location monitorsthermal response of the specimen,thermal response of the specimen,yielding the absorption spectra.

Active Infrared Multispectral Imaging to Identify Chemicals on Surfaces

- Anish K. Goyal

Summary

• Mid‐IR fingerprint is rich region• Broad Tuning facilitates spectral sensing• Broad Tuning facilitates spectral sensing• ECqcL™ architecture harnesses broad gain• Single chip tuning continues to increase• Enables molecular detection for solids, liquids and gas.

• Absorption Spectroscopy and Imaging effectivep p py g g