Transcription
QCL2006Recent Updates inQCL- and ICL-based ApplicationsJoel M. HensleyPhysical Sciences Inc.Andover, MA2nd International Workshop onQuantum Cascade LasersSeptember 5-10, 2006Brindisi, ItalyPhysical Sciences Inc.20 New England Business CenterAndover, MA 01810
Introduction and Outline QCL2006-1PSI serves both government and industrial customers in many markets:– AeronauticIQ/CL Applications include– Automotive– Engine exhaust gas analysisQCL– Environmental– Communications– Medical– Exhaled breath analysisGroup– Military– Mapping of atmospheric species– Pharmaceutical– Stand-off detection of:– Security-related chemical warfare agents toxic industrial compounds1. Multi-QCL multi-species gas analyzer for SO2 and SO3– oil-consumption sensing in automobile engine development2. ICL-based ambient methane sensor– evaluation of air quality and carbon sources/sinks in atmosphere3. ICL-based ethane breath sensor– detection of reactive oxidative stress for assessment of exposure to environmentaltoxins4. QCL seeded OPO for LIDAR transmitter– narrow-linewidth MWIR source for space-based atmospheric monitoring
1) SOx Spectroscopy in Engine ExhaustsQCL2006-2 700 K, 0.2 atm, 60 ppm SO2, typical combustion products0.035Sensor LayoutAbsorbance Per 001330 1330.513311331.5 13321332.5Spectral Frequency, cm-113331333.5Target blended feature:1332.4 cm-1 for SO2, 1396.6 cm-1 for SO31334G-2037 Laser for each species Balanced detection Insensitive to changesin broadening
Calibration of SOx Absorption SensorQCL2006-3300 Torr total pressureNEA2 x 10-4 Hz-1/2- or 1 ppm-m/Hz1/2of SO2SO220 Torr total pressureSO3 First laser spectroscopy measurements of SO3NEA1 x 10-4 Hz-1/2- or 2 ppm-m/Hz1/2of SO3
2) ICL-based Ambient Methane SensorQCL2006-4 Cryogenic ICL– 5mW at 3.4µm– 3mA thresholdat 80K CH4 ν3 transitions:2937 to 2938 cm-1 6.8m optical path 2 TE-cooled InAsdetectors rms precision is 15 ppbv for 60s integration time– Calibrated in lab and tested in University of New HampshireField Test Site
UNH Field Test Site Sallie’s Fen QCL2006-5Aerial ViewwwSampling Chambersud.eh:to .unoG aprmi.awBase Station Regional air quality monitoring network 10 chambers networked to central basestation. Hand samples for CH4 by gaschromatography Ten year measurement archive Operates around the clock Automatically samples CO, O3, SO2, CO2,NO, NOy Hg, aerosols, andvolatile organic compounds
Methane Measurements at Sallies’ Fen 7/20/06 12:00 EDT QCL2006-6Chambers [1-10] open to ambient for 8 min to flush, then close for 10 minResults in build up of CH4 and CO285UNH GC7CH4 [ppmv]9PSI :0013:00:0016:00:0017:00:00EDT [HH:MM:SS] Excellent agreement with co-located gas chromatograph (GC)18:00:00
3) ICL-based Ethane Sensor using ICOS WMS QCL2006-7CW ICL laser at 3.3µm– 0.1 mW– LN2 cooled– 1.5 cm-1 current tuningrange at fixed temp1000.014T 121.8K @ 22mA0.0120.010.0080.0060.0040.002 32mA28mA20mA22mA16mA12mAC2H6 (100ppm-m)85800752970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980Wavenumber (cm-1)ICOS cell– Mirrors have R 99.98% 90TE-cooled InAs detectorTransmission (%)Relative Signal (a.u.)95 Single board controllerG-5708––––Battery poweredDrives laserProcesses WMS signalContinuous output at 10Hz
Ethane Sensor PerformanceQCL2006-8 Single pass through 50cm cell with 949 ppm ethane Tune across ethane absorption line at 2977 cm-1 Demodulated WMS Ouput Signals– 0.1ms integration time– Ethane shut of at t 180 s949f1f2conc20000Ethane (ppmv) Normalized absorption featureSignal (counts)25000150001000050000 0100200300400Time (sec)5006000H-1816aResults with ICOS cell– 800 meter effective path length– Detection limit 30 ppb in 0.4 s
4) QCL Seeded Optical Parametric Oscillator (OPO)QCL2006-9850mJ ( 2.5ms)Tm:YALO Laserat 1.940µm70mJ (6ns)Ho:YLF Laserat 2.055µmHWPpPumLEGENDHWP: Half-wave plateM1: HR at 5µm, 45 M3: HT at 2.1µm, 50%R at 3 to 5.5µmM2: HR 2 to 5.5µmTFDP: Thin-film dielectric polarizerS1: Rotary stage for ZGP angle tuningS2: 1-axis translation, 2-axis angle stage4700mJ (3ms)Diode Laserat 0.793µmdSeeCryogenicM14.6µmQCLQCLDFB& driveelectronicsrunningcwM2up to 20mWTFDPM1M3S1S2ZGPZGPS1M1 ZnGeP2 crystal Ring geometry– No isolatorrequired Type 1 phasematching 100nmbandwidthOutputexpect 7mJ at 4.6µmline-narrowed Injection seeding to achieve narrowlinewidth OPO emission
Grating Spectrometer View of OPO OutputQCL2006-10 Pump OPO with 10mJ of 2.055 µmNo seedingWith 0.5mW seeding from QCLGrating DirectionBroadband, very low energy1.5 mJ of narrow band 4.6 µm First demonstration of QCL seeded ZGP OPO– Also working on QCL-seeded CdSe OPO for LWIR
Ongoing ActivitiesQCL2006-11 THz QCL programs– Differential absorption LIDAR for stand-off explosives detection– Optical heterodyne for free-space communications Atomic oxygen sensor for high temperature flows– 63 µm cryogenic QCL in external cavity See Thursday’s talk by Alessandro Tredicucci Broadly tunable LWIR QCL laser system– 8 µm QCL, cryogenic and room temperature– Angled facets and AR coatings– Coupled to external diffraction grating
AcknowledgementsQCL2006-12Physical Sciences, Inc.Mark G. AllenDavid M. SonnenfrohDavid I. RosenMichelle L. SilvaRick T. WainnerKrishnan R. ParameswaranQ-PeakGlen RinesJeff ManniPeter MoultonJohns HopkinsTerrence R. RisbyUniversity of New HampshireRuth K. VarnerSNS - NESTAlessandro TredicucciJihua XuRichard GreenCambridge UniversityHarvey E. BeereDavid A. Ritchie
QCL- and ICL-based Applications Joel M. Hensley Physical Sciences Inc. Andover, MA 2nd International Workshop on Quantum Cascade Lasers September 5-10, 2006 . Calibration of SO x Absorption Sensor 2 x 10-4 Hz-1/2-or - 1 ppm-m/Hz1/2 of SO 2 SO 2 300 Torr total pressure 20 Torr total pressure SO 3 NEA
