Primo Workshop Nazionale su: La Componentistica Nazionale per lo Spazio: Stato dell arte, Sviluppi e Prospettive Realizzazione di un sistema LiDAR basato su fotomoltiplicatori in silicio Roma, 18 2 gennaio 216 G. Adamo, A. C. Busacca DEIM, Università degli Studi di Palermo, Viale delle Scienze, Ed. 9, 9128 Palermo, Italia
Outline Introduction Our LiDAR Front-Ends with SiPM and APD Preliminary TOF measurements Varying the distance from the target At different intensities of ambient light Conclusions
The uses of LiDAR Airborne LiDAR Mapping: Mapping and Cartography of Planets, Forestry Management and Planning, Flood Modelling, Pollution Modelling, Urban Planning, Coastline Management, Transport Planning, Oil and Gas Exploration, Quarries and Minerals (Volumetrics and Exploration), Archaeology, Landing of Space Modules, Cellular Network Planning http://www.geoconnexion.com Ground-based LiDAR Mapping: Automated Guided Vehicles, Mapping of Scene of Accident/Crime, Architecture, Building Restoration, Sewer Maintenance, Meteorology, Geology, Physics and Astronomy, Military and Law Enforcement https://www.youtube.com
APD Avalanche Photodiode The Si-APD SAR5H4 includes a Silicon Avalanche Photodiode with a low noise preamplifier Main application: high speed, low light detection laser range finding and LiDAR Si-APD Laser Components SAR5H4 Breakdown voltage Operating Bias 175 V 164 V Power Consumption 15 mw Package diameter 5.31 mm Active area diameter 5 µm Peak responsivity.4 MV/W at 95 nm Bandwidth 2 khz 47 MHz Price 29
SiPM Silicon Photomultiplier Parallel array of APDs (cells), working above their breakdown voltage, with individual integrated quenching resistors The cells are connected to a common analog output to produce a summation signal proportional to the number of detected photons SiPM STMicroelectronics SPM42H6-6P Breakdown voltage Operating Bias 28 V 3 V Power Consumption < 6 mw Package dimensions 5 x 5.5 mm 2 Active area dimensions 3.96 x 4.44 mm 2 Number of cells 4871 Fill factor 62% Price ~ 8 $
SiPM vs APD & PMT APD PMT SiPM Cost Operating bias Encumbrance Strength Gain Responsivity Dynamic operating range
Comparison of the APD and the SiPM responsivities Responsivity [MV/W].45.4.35.3.25.2.15.1.5 Bias 164 V Responsivity [MV/W] 15 T = 25 C T = 25 C 35 3 25 2 1 5 Bias 27.6V 28.V 29.3V 3.8V 32.8V 4 6 8 1 [nm] APD Laser Components SAR5H4 BV = 175 V Bias = 164 V 4 5 6 7 8 [nm] SiPM STMicroelectronics BV = 28 V Bias = 3 V
LiDAR Front-End with SiPM Stop SiPM (with bandpass filters) Start SiPM Laser driving circuit Lenses
Laser Driving Circuit Laser model: Osram SPL LL9_3 Pulse duration: 35 ns Peak optical power: 7 W Emission wavelength: 95 nm Pulse repetition frequency: < 25 khz (Laser class 1 IEC 6825-1) Introduction Our LiDAR Front-Ends TOF measurements Conclusions
Comparison of the APD and the SiPM biasing circuits APD Laser Components SAR5H4 SiPM STMicroelectronics SPM42H6-6P
TOF Measurements - 36 m - Indoor.9.8.7 APD stop.6.5 [V].4.3.2.1 242 ns 36.3 m -1 1 2 3 4 5 6 7 8 Date & Time: 13/1/216 19: SNR : 13 SNR APD stop: 18
TOF Measurements 214 m 257 m 36 m 36 m
TOF Measurements - 36 m - Outdoor.2.15 APD stop 8 7 6 APD stop 5 [V].1 [mv] 4 3.5 2 1 242 ns 36.3 m 2 4 6 Weather: sunny Date & Time: 5/1/216 12:15 1 2 3 SNR : 3 SNR APD stop: 8
TOF Measurements - 214 m - Outdoor.18.16 8.14.12 6 [V].1.8 [mv] 4.6.4 2 143 ns 214.5 m.2 5 1 15 Weather: sunny Date & Time: 5/1/216 12: 5 1 15 SNR : 1
TOF Measurements - 214 m - Outdoor 1.4 1.2 1 4 35 3 25 [V].8.6 [mv] 2 15.4.2 1 5 143 ns 214.5 m -1 1 2 3 4 Weather: clear Date & Time: 5/1/216 17: 5 1 15 SNR : 14
TOF Measurements - 257 m - Outdoor.16.14 7 6.12 5 [V].1.8.6.4.2 5 1 15 2 Weather: sunny Date & Time: 5/1/216 12:45 [mv] 4 3 2 1-1 171 ns 256.5 m 5 1 15 2 SNR : 7
TOF Measurements - 36 m - Outdoor 1.2 6 1 5.8 4 [V].6 [mv] 3.4.2 1 2 3 Weather: clear Date & Time: 23/12/215 17: 2 1 24 ns 36 m 5 1 15 2 25 SNR : 22
Conclusions Experimental comparison of LiDAR front-ends with SiPMs and with APDs in terms of maximum detected distance and at different intensities of ambient light. Milestones Work in progress Step 1 Introduction on LiDAR Step 2 Our LiDAR Front-Ends with SiPM and APD Step 3 TOF measurements Optimization of our lens system in terms of performance, encumbrance and cost Implementation of a TDC board and a peak detector in order to obtain a complete, stand-alone, LiDAR with SiPMs.
Conclusions Gabriele Adamo DEIM University of Palermo, Viale delle Scienze Bldg. 9, 9128 Palermo - Italy gabriele.adamo@unipa.it