Mid-IR sensing using external cavity quantum cascade lasers (EC-QCL) Timothy Day, David Arnone, Miles J. Weida, Michael Pushkarsky, Dave Caffey, Vince Cook, Chris Armacost Daylight Solutions, Inc. www.daylightsolutions.com
Outline Applications in Molecular Detection External Cavity Review and Recent Tuning Results Molecular Detection and Recent Performance Mid IRIlluminationandRecent Illumination and Recent Performance Summary
Date June 06 Mar 07 June 07 Sept 07 Dec 07 Product Broadly tunable mid IR laser systems for scientific applications High sensitivity, low noise mid IR detector/receiver Battery operated illuminator for commercial & military applications Broadly tunable, MHF laser systems for Scientific Applications Swept Sensor, portable OEM sensors for molecular detection Oct Ot08 Fixed wavelength aelengthcw and pulsed illuminators for OEM applications Platform Portfolio Date Product Mar 09 High power multi band ut laser systems (limited release) Oct 09 Mar 10 Mar 10 Jan 11 Size, weight reduction, environmentally ruggedized packaging Added capabilities, platform specific packaging, system integration Ruggedized fiber cable LRU Ultra broadly tunable mid IR laser systems (> 300 cm 1 ) High Powered, Air Cooled, Fixed Wavelength Laser Systems
Molecular lar Detection Glucose Monitoring High Speed, Portable, Swept Sensor Systems Medical Breath Diagnostics Infrared Imaging Hospital lanesthesia Monitoring Imaging Spectroscopy Scientific Instrumentation Platform technology utilized in multiple applications Breath Alcohol Detection Environmental Monitoring Networks
Why Mid IR? CH 4 SO 2 COS H 2 S glucose ethanol Liver disease Asthma Blood glucose End-stage renal disease H. Pylori/Stomach ulcer Diabetes Breath alcohol Health Industries
Why Mid IR? CH 4 SO 2 N 2 O aromatics SO 3 H 2 S glucose COS SO 2 ethanol H 2 SO 4 Atmospheric Sciences
Common Explosives & CWA Agents
The Source for all Applications in the Mid-IR Why is Broad Tunability Important? Narrow tuning reveals only a snapshot. Laser scan Lasers Technical Seminar, Lahat Technologies Ltd.
Broad Tunability bl The Source for all Applications in the Mid-IR Laser scan Broad so tunability you can see reveals the the entire whole fingerprint picture!!! Lasers Technical Seminar, Lahat Technologies Ltd.
Why is Broad Tunability Important? Composite spectrum Daylight Solutions broad tuning >250 cm -1 Deconvolved spectrum Daylight Solutions broad tuning >250 cm -1 Absorbanc ce Absorbance eh2o Ethanol 2 CO 2 950 1000 1050 1100 1150 1200 Wavenumber (cm-1) 950 1000 1050 1100 1150 1200 Wavenumber (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 Results
Sub threshold Gain CO 2 > 700 cm 1 4 µm 5 µm Broad gain must be managed to provide usable light Distributed Feedback (DFB) QCLs Sacrifice gain and yield QCLs don t function as SLDs Et External lcavity 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 Incre easing Cur rrent 920 ma 30 cm 1 4.0 µm
External Cavity quantum cascade Laser (ECqcL ) 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 (Peak. power)
Beam Characteristics Beam Divergence - < 5 mrad Polarization - Linear 100:11 Beam Quality - Pointing Stability - TEM00 < 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 increase Faist, J., et al., Science, 264, pg. 553 (1994) Maulini, R., et al., Appl. Phys. Lett., 88 (20), pg201113 (2006) Luo, G.P. et al., Appl. Phy. Lett. 78, pg 2834 (2001) Wittmann, A., et al., IEEE J. Quant. Elec., 44 (11), pg. 1083 (2008) Gmachl, C., et al. IEEE J. Quant. Elec., 38(6) pg 569 (2002) Hugi, A., et al., Appl. Phy. Lett., 95, pg. 061103 (2009) Maulini, R., et al. Appl. Phys. Lett., 84 (10), pg. 1659 (2004)
Molecular Detection Applications and Recent Performance
Vapor Analysis Using Swept Source ethanol methanol IPA PNNL database reference
Molecular Detection Example: Environmental Monitoring Beijing Olympics
Accessing 3.x µm Type I GaSb diodes incorporated in external cavities 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 5 Pulsed Tuning Performance Pulsed and cw operation at 315 3.15 µm Power (mw) 4 3 2 1 0 3370 3270 Wavenumber (cm -1 ) 3170 3070 500 ma Access to acetylene and 400 ma 375 ma methane C H stretch absorption spectra (PNNL simulations) Power (mw) 6 5 4 3 2 CW Tuning Curve 500 ma 400 ma 300 ma cw tuning 2.93-3.26 µm 345 cm -1 of tuning (11% of center wavelength) 1 0 3370 3270 Wavenumber (cm -1 ) 3170 3070 Next generation at 3.25 um and reached 9 mw CW
Mode Hop Free (Phase Continuous) Tuning 0.002 cm 1 linewidth Mode Hop Free tuning Required for high resolution spectroscopy applications
Mod Hop Free Tuning 121 cm 1 (>250 nm) of MHF tuning Dips in gain curve are atmospheric 13 CO 2 absorptions Withselected chip, isotopic ratio measurement ispossible New MHF chips centered at 4.3 and 5.5 µm are in the works
Classic Protein Folding Dynamics Amide I Band
University of Vienna: Professor Lendl Simultaneous determination of glucose and lactate in aqueous phase Schematic representation of the QCL based transmission setup. Absorption spectra of pure analytes dissolved in Ringer solution
Mid IR Illumination Applications and Recent Performance
Standoff Detection of Explosives with EC QCL Frank Fuchs - Fraunhofer-Institut The sensor head comprises the tunable external quantum cascade cavity laser, an IR imager, and a visible camera. The system software enables automatic ti identification.
Hyperspectral Microscopy with EC QCL for explosives detection M. C. Phillips, J. D. Suter, and B. E. Bernacki - PNNL (a) The EC-QCL illumination is transmitted through the sample, and a magnified ( ) Q g p, g image is detected using an infrared microbolometer camera. (b) Tuning curve of ECQCL illumination. (c) Representation of hypercube containing transmission images taken at 100 wavelengthbands.
Broadband IR spectroscopy of SiO 2 using ssnom and QC Lasers UCSD Dimitri Basov Lightning Rod Effect Localizes E fields to tip AFM tip = 10nm radius λindependent* 10nm 1 µm: Diameter of human nerve cell 800 nm: giant virus Mimivirus 150-250 nm: small bacteria ~100nm: domains in organic semiconductor films IR TGQ1 Si Ampl. 22nm Instrumentation 2nm SiO 2 SiO 4.4 11.3μm imaging 2 <1min point spectra Phase 20 20 2nm resolution
Summary Mid IR fingerprint is rich region 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 pyand Imaging geffective