Lasers Technical Seminar at Bruno Events Center on March 27 th, 2012 Next generation of SPADs - Single Photon Avalanche Detectors LASER COMPONENTS, 2012
Lasers Technical Seminar, Tel Aviv March 27 th, 2012 Laser Components Group Single Photon Counting Detectors Overview Linear and Geiger Mode APDs Quenching Circuit SPAD Modules Technical Background Product Performance Further Improvements and Next Generation Applications Page 2
The LASER COMPONENTS Group Laser Components GmbH (Germany) Laser Components UK Ltd. (United Kingdom) Laser Components Canada, Inc. (Canada) Laser Components S.A.S. (France) Laser Components DG, Inc. (USA) Laser Components IG, Inc. (USA) Page 3
The LASER COMPONENTS Group Product Portfolio In-house Production Detectors Laser Diodes Measurement Technology Fiber Optics Optics Laser optics Laser diodes Fiber assemblies APDs Photon Counters Pulsed laser diodes Laser modules Conversion Screens UV detectors NIR detectors IR detectors Pyro detectors Thermopiles PSDs CW laser diodes Pulsed laser diodes High power LDs VCSEL QCLs Lead salt lasers LEDs Energy and power measurement Laser alignment Laser light barriers IR spectrometers Fiber optical sensors Thickness measurement Optical fibers Fiber assemblies Couplers / WDMs Connectors Modulators Fiber Tools Optical Switches Laser optics Optical filters Diffractive optics IR laser optics E/O Components Optical gratings Laser rods and crystals Page 4
LASER COMPONENTS GmbH Vision: Development, production and distribution of custom laser-based and optoelectronic components Established in 1982 Located in Olching, Germany ISO 9001:2000 certified Production of PLD and APD electronics, Photon Counting Modules, Laser Diodes, Laser Optics, Laser Modules, Fiber Asemblies, Convertion Screens Page 5
LASER COMPONENTS DG, Inc. Vision: Produce high performance avalanche photodiodes and subsystems meeting and exceeding market expectations Established in 2004 Located in Tempe, AZ ISO certified Production of both Si and InGaAs avalanche photodiodes, hybrids Page 6
PicoQuant GmbH Vision: Produce robust, compact and easy-to-use time resolved electro-optical instrumentation and systems Established in 1996 Located in Berlin, Germany ISO 9001:2000 certified Production of picosecond lasers, time-resolved fluorescence spectrometers and photon counting systems Page 7
Background Low Light Levels 100E+6 10E+6 N( ), Number of Photons / second 1E+6 100E+3 10E+3 1E+3 100E+0 N( ) = 5.03 E15 x x P where is wavelength in nm and P is the optical power 400 nm 630 nm 830 nm 1060 nm 10E+0 1E+0 1E-18 10E-18 100E-18 1E-15 10E-15 100E-15 1E-12 10E-12 P, Optical Power (watts) Page 8
Overview about Single Photon Counting Detectors Photomultiplier Tubes (PMT) + Large Active Area + Low Noise +/- Different Cathode Materials - Poor sensitivity - High Sensitivity to Magnetic Fields - High Voltage EMCCD + Multiple Pixel Information - TE Cooling to 100 C - Very Expensive Page 9
Overview about Single Photon Counting Detectors Si-PM + Multiple APD Pixels + Good timing resolution (100 ps) + Low operating voltage (40 to 100 V) + Cheap thanks to convential CMOS techniques - Poor sensitivity - High Noise CMOS + Very Good timing resolution (40 ps) - Low sensitivity - Extremely Small Active Area (10 50 µm) Page 10
Overview about Single Photon Counting Detectors Single Photon Avalanche Detector (SPAD) + Best Detection Efficiency + Low Noise + Good Timing + Compact Size + Wide Spectral Sensitivity + Very short Afterpulsing + No Sensitivity to Magnetic Fields - Small Active Area (100µm. 180µm) - High Voltage Page 11
APD Background Linear Mode Linear mode APD SAE-series SAR-series IAG-series etc. 1000 100 +75 C 10 Vop < Vbr (linear range) M typically 10 250 depending on APD type 1 50 70 90 110 130 150 170 190 210 230 250 Bias Voltage Page 12
APD Background Geiger Mode Geiger mode APD SAP-series SAV-series (VLoK) Responsivity (A/W) 1000 100 10 1 0 70 80 90 100 110 120 130 140 Bias Voltage (V) Resp(22 degc) Resp(-40 degc) Vop > Vbr (Geiger mode range) M up to 10 8 achievable Quenching circuit required Page 13
APD Background Quenching Passive quenching circuit example Current limiting resistor R s If R s is sufficiently large, I photo < I latch quenching Slow recovery (RC time constant) Dead time not clearly defined Page 14
APD Background Quenching Active quenching circuit example Lower V op temporarily below V br Faster recovery Well-defined dead time Page 15
SPAD Module Design goals Extremely low dark count level Large active area Detection efficiency (red) to meet / exceed industry standard Detection efficiency (blue) to exceed industry standard Mechanical compatibility with existing photon counters RoHS compliance Page 16
COUNT Module Page 17
COUNT Module Dimensions Page 18
COUNT Module - Features VLoK Geiger mode silicon APD Built-in TEC and thermistor Specially developed active quenching electronics Gating function Compact, robust package Single 12V DC voltage supply required Optional FC connector for fibre optics Page 19
COUNT Module - APD Noise considerations i 2 n 2q[ I s ( I dm I bk ) M ² F] where q : Electron charge I s I dm I bk : Non-multiplied component of the dark current : Multiplied component of the dark current : Background photocurrent M : Multiplication gain F : Excess noise factor Page 20
COUNT Module - APD Excess noise factor F k eff M ( 1 keff )(2 1/ M ) Design goal is Very Low K factor (= VLoK) Page 21
COUNT - Series Established in October 2010 Winner NASA Tech Briefs Award product of the year High detection efficiency and short afterpulsing QE > 70% @ 670 nm < 0.5% afterpulsing < 10 c/s available Page 22
COUNT blue Series New addition to the COUNT series Introduced at Photonics West 2011 Even higher short wavelength detection efficiency QE > 55% @ 405 nm QE > 70% @ 532 nm < 0.5% afterpulsing < 10 c/s available Page 23
COUNT Module Detection Efficiency Photon Detection Efficiency (%) 90,00 80,00 70,00 60,00 50,00 40,00 30,00 20,00 10,00 0,00 400 500 600 700 800 900 1000 1100 Wavelength (nm) Page 24
Photon Counting Module Comparison Parameter SPCM COUNT COUNTblue Dark count rate - min. (Hz) 25 10 10 Pd @ 670 nm - minimum (%) 50 60 50 Pd @ 670 nm - typical (%) 65 70 55 Pd @ 405 nm - minimum (%) 2 5 50 Pd @ 405 nm - typical (%) 5 15 55 Nominal active area dia. (µm) 170 100 100 Afterpulsing probability - typ. (%) 0.5 0.5 0.5 Timing resolution - typ. (ps) n/a 800 800 Dead time - typ. (ns) 32 70 70 Operating voltage (V) 5 12 12 Page 25
COUNT Photon Counting Module Photon detection efficiency (P d ) profile Page 26
COUNT Module Typical Data Status: March 5 th, 2012 S/N Modultyp Dunkelzählrate [c/s] Afterpulsing [%] Totzeit [ns] Pd Freistrahl [%] @670nm Pd Freistrahl [%] @405nm A6143 COUNT-blue 14,8 0,05 51 72 65 A6148 COUNT-blue 13,4 0,06 52 72 59 A6149 COUNT-blue 19,6 0,08 52 72 64 A6151 COUNT-blue 12,7 0,05 52 71 62 A7301 COUNT 7,1 0,11 55 69 50 A9842 COUNT 131,2 0,16 53 81 28 A9851 COUNT 139,1 0,15 52 83 29 A9852 COUNT 125,8 0,15 52 80 30 A9864 COUNT 151,9 0,16 51 79 29 A9871 COUNT 26,2 0,1 51 80 30 A9881 COUNT 10,1 0,11 52 81 26 B0466 COUNT 197,3 0,55 51 82 43 B0467 COUNT 200,3 0,78 69 84 43 Page 27
COUNT Module Accessories COUNT PSU power supply: Low-ripple mains supply with matching LEMO connector DSN102 dual power supply Powers two COUNT modules Integrated counter Automatic shut-down when over-illuminated Fibre optic assemblies Fibre core diameters from 50-100 µm Light-tight buffer and connector (SMA, FC/PC) assemblies Page 28
COUNT Series Product Improvements Burn-in Analysis showed that isolated incidences of infant mortality failure may occur within the first 3 5 days of operation. Tests showed that this could be avoided by an adequate burn-in A standard 5-day burn-in before end test was added to the production. Burn-in rack allows simultaneous burn-in of up to 10 modules. Page 29
COUNT Series Product Improvements Improved test capability QE test @ 810 nm added in May 2011 Gating function test bench available on demand Module test sheet contains Module type Serial number DCR QE at 405, 670, 810 nm Afterpulsing probability Dead time Page 30
COUNT Series Product Improvements Electronic version 2.0 Reduced afterpulsing Improved temperature regulation Optimized output pulse shape Page 31
COUNT Series Product Improvements Optimized fiber coupling AR/AR-coated GRIN lenses LC in-house IBS coating FC connector loss < 5 % COUNT standard FC connector loss < 4 % COUNT blue Page 32
COUNT Series Product Improvements Higher detection efficiency QE optimization by APD overvoltage available upon request Screening options Dark count rate Detection efficiency Afterpulsing Operating Voltage [V] Overvoltage [V] QE @ 405nm [%] QE @ 670nm [%] QE @ 810nm [%] Dark count rate [c/s] Afterpulsing [%] 346.3 2.0 30 55 32 15.4 0.04 61 348.4 4.1 36 69 43 31.4 0.11 55 350.6 6.3 40 79 51 57.4 0.24 51 352.3 8.0 43 85 55 91.4 0.42 50 Dead time [ns] Optimised window (COUNT blue ) AR/AR-coated UV quartz window 355.0 10.7 45 90 60 138.2 0.89 49 Page 33
T-SPAD - Series Faster Timing Resolution Down to 350 ps (FWHM) For Fluorescence Lifetime Imaging (FLIM) NIM and TTL signal output Page 34
Future Products COUNT NIR Existing COUNT module further optimized for 810 nm Goal: highest possible detection efficiency to enable quantum cryptography technology Page 35
Future Products LC Group CONFIDENTIAL COUNT Q1500 InGaAs-based single photon counting module Goal: to provide a long wavelength alternative for long-range quantum communication at 1550 nm Prototype successfully demonstrated in December 2011 Market introduction planned for Q4/2012 Page 36
Photon Counting Applications Particle sizing Confocal microscopy Time-resolved fluorescence detection Astronomy Quantum cryptography Page 37
Applications - Particle Sizing Dynamic light scattering Also known as Photon Correlation Spectroscopy, PCS Doppler shift measurement on moving particles Particle diameter from <1 nm to > 1 µm Detector typically Photon Counting Module or PMT Page 38
Applications Confocal Microscopy Laser-induced fluorescence Point sensor principle Spatial filtering for elimination of extraneous light Reduced depth-of-field = higher resolution Composite view from series of optical sections allows 3D imaging Detector: SPAD or PMT Page 39
Applications Confocal Microscopy Wide variety of applications in cell / tissue studies, protein research, drug discovery, stem cell research Fluorescence Lifetime Imaging Spectroscopy (FLIM), time-resolved analysis Fluorescence Resonance Energy Transfer (FRET), high spatial resolution of protein interactions (molecular level) Page 40
Applications - Astronomy Long-range LIDAR Adaptive telescope optics Page 41
Applications Quantum Cryptography Quantum key distribution use of quantum communication to securely generate a key for two parties (Alice & Bob) to securely communicate Requires single photons with correlated quantum states to be sent to Alice and Bob simultaneously Immune to eavesdropping any third party attempt (Eve) will disrupt the quantum states of the photons Free space or fiber use Alice and Bob need single photon detectors Page 42
LASER COMPONENTS Manufacturer Distributor Partner LASER COMPONENTS, 2012