signal strength monitor for c-spad receiver · rec. energy: meas. by ppet (compens.delay) 4.0 4.6...
TRANSCRIPT
SIGNAL STRENGTH MONITOR FOR C-SPAD RECEIVER
Ivan Prochazka, Karel Hamal
presented at
14th International Workshop on Laser Ranging, San Fernando, SpainJune 7-11,2004
Czech Technical University in Prague, Czech Republic
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Goals:
n to estimate the echo signal strengthin laser ranging based on C-SPAD detector
n the SPAD chip current pulse risetime dependson photon number (Kirchner, Koidl, 1995)
n C-SPAD circuit provides two output timingpulses, their interval corresponds to thedetected signal energy
n to construct the Time to Digital Converterto record the interval and hence the echo sinalenergy
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
C-SPAD Detector Package # 0406
n avalanche build up time effect expanded by built-in circuit(G.Kirchner, F.Koidl)
n large data sets averaging
SPAD UNIT 0406 / GRAZMeasured: Delay (Comp-Uncomp Output) with PPET
<Graz, 1998-08-26>
0
-39
-84.5-116
-141-163
-192
-243
0 0 2 7 12 12 9
-4
1 10 100 1000
0
50
100
-50
-100
-150
-200
-250
-300
Compensated Output [ps]
UN-Compensated Output [ps]
Delay: 210 ps;==> 280 Photons
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
SLR with Photon Number Estimate
G. KIRCHNER1), F. KOIDL1), I. PROCHAZKA2), K. HAMAL2,,11th WLRI, Deggendorf, 1998
RMS vs. Received # of PhotonsRec. Energy: Meas. by PPET (Compens.Delay)
<Graz, 1998-09-11>
4.04.6 4.6
4.33.7 3.5
3.0
9.38.8
8.3
5.9
5.0
1-3 3-10 10-30 30-100 100-300 300-1000 > 10003.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0LAG-1 : All Rets: 9.4 mm
LAG-2 : All Rets: 9.3 mm
ERS-2: All Rets: 4.3 mmLAGEOS
ERS-2
SLR data post processing, data averaging
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Photo Number EstimateIndoor Calibration Tests
n compensated versus un-compensated output
n shot by shot data processing
n PET4 timing, NdYAG 32 ps @ 532 nm, indoor
89,0 89,1 89,2 89,3 89,4 89,5 89,69,4
9,5
9,6
9,7
9,8
9,9 pulse width 35 ps
Unc
omp.
- c
omp.
del
ay [n
s]
Uncompensated range [ns]
1 PE 10 PE 100 PE 1000 PE
n data spread ~ 50 ps rms
n = > ultimate photonnumber resolution 3 x
J. Blazej et al, NIST-ARDA Workshop on SinglePhoton Detectors,NIST, Washington DC, 2003
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Time to Digital Converterfor C-SPAD Based Energy Monitor
n REQUIREMENTS:
n resolution 20 ps
n range 8 bits / ~ 1.6 ns
n dead time < 400 us
n DESIGNED CIRCUIT
n time expander, capacitor charge / discharge
n expansion factor ~ 2ooo x
n digital counter 30 / 15 ns on Programmable Gate Array
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Time to Digital Converter Calibration
~ 100 channels / 1.6 nsec
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Indoor Laser RangingTestPrague, June 2, 2004, 2 kHz, 32 ps laser diode, C-SPAD, PET2k
n 1 PE 23 ps rmsdark count
n 1 ~ 10 PE 23 ps
n ~ 100 PE 12 ps
n ~ 1000 PE 8 ps
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Ground Target Laser RangingEnergy Spectrum
Graz, May 5, 2004, 2 kHz, 8 ps laser, C-SPAD, PET2k
dark counts / stability2 series, 24 hour appart
1 m ground target ranging1 - 10 PE, 15 ps rms
4 km ground target ranging~ 1000 PE, 6 ps rms
I.Prochazka,K.Hamal, San Fernando, Spain, June 2004
Conclusion
n the C-SPAD based receiver package energy monitorhas been constructed and tested
n FEATUES:
n built in the PET2k
n 7 energy levels resolution / shot - by - shot1-3, 3-10, 10-30, 30-100, 100-300,300-1000, > 1000
n self - calibrating /via dark counts on 1 PE/
n temperature & temporal stability < 0.1 ch / day
n STAND BY device of the C-SPAD energy monitorhas been constructed and is available for SLRstations operating C-SPAD