1. I. Prochazka 1, J. Kodet 1,2, J. Blazej 1 K.G. Kirchner 3, F. Koidl 3 Presented at Workshop on Laser solutions for Orbital Space Debris 27 - 28 April 2015,Laboratoire APC, Université Paris Diderot, Paris, France 1 Czech Technical University in Prague, Prague, Czech Republic 2 TU Munich, Geodetic Observatory Wettzell, Bad Kötzting, Germany 3 Space Research Institute, Austrian Academy of Sciences, Graz, Austria Solid State Photon Counters for Laser Ranging to Orbital Space Debris

2. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 OUTLINE n Requirements put on detectors n Detectors available - review n Si SPAD detectors n Ge, InGaAs SPAD detectors n Superconducting detectors n Conclusion

3. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Requirements put on detectors for space debris laser ranging n EXPERIMENT ENERGY BUDGET = > single photon response high Photon Detection Efficiency (PDE) n LASER SOURCES AVAILABLE & SAFETY = > sensitive @ 532 or 1064 or 1550 nm n OPTICAL TRACKING TELESCOPE FoV = >detector aperture >= (50) 100 um n FIELD OPERATION, ROBUST AND RELIABLE

4. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Photon counting detectors key parameters for laser ranging n VACUUM / PHOTOCATHODE based Apertures 1 mm.. 1 meter Wavelength rangeUV ….. 1550 nm Photon Detect.Eff. 30 % ….0.1 % n SEMICONDUCTING detectors Apertures up to0.5 mm Wavelength 532... 1064 nm Si 532... 1550 nm Ge / 77K 1064. 1550 nm InGaAs PDE70 %.. 1 % Si n SUPERCONDUCTING detectors (kryo-cooled) Apertures max.10 um (50 um ?) Wavelength532 …. 1550 nm PDE> 50 % @ 1550 nm Si SPAD 500um, TE cooled Superconducting detector 10 x 10 um Hamamatsu photomultipliers

5. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Single Photon Detectors made by CTU since 1984 Si,200 um,TE cooled GaAs messa GaAsP, 350 um Complete detector packages 60 mm 130 mm Detector chips Active quenching and gating circuit I. Prochazka, Phys. Status Solidi, Vol 2, No.5, 1524-1532 (2005)

6. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Si SPAD Detector Package for SLR n Detector aperture 200 um, f/D=1, => acceptable FoV n Photon Det. Efficiency >~ 30 % @ 532 nm n Used by > 20 SLR stations worldwide n Applied for the first space debris laser tracking demonstration n Self-consistent compact package n SPAD 200 um, 3 x TE cooled in vacuum n collecting optics f/D = 1.0 n active quenching and gate circuit n 50 x 50 x 130 mm, 300 g I.Prochazka et al, Rev. Sci. Instrum. 84, 046107 (2013 )

7. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 SPAD detector package for SLR applied for space debris laser tracking Shanghai, China, discarded US rocket (ID 2007-006G) July 17, 2008 Mt. Stromlo, Australia, 2003 www.eos-aus.com/space/education /..

8. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 SPAD detector package with high PDE for space debris tracking n High Photon Detection Efficiency PDE n SAP500 detector by Laser Components n APD on Si, 0.5 mm diameter, ~ 100 V break. n PDE exceeds 60 % @ 532 nm @ 15V ab (M.Stipcevic, 2011)

9. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 SPAD detector package with high PDE #2 for space debris tracking n HQE Detector package developed n Standard SPAD housing & optics n Single TE cooling to -8 o C n 1 : 1 replaceable to other SPADs detectors at SLR systems mechanics/optics/signals/cables 220 ps @ 15V ab < 25 kHz @ 15V ab Prochazka I, et al, Journal Advances in Space Research, JASR11779

10. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 SPAD detector package with high PDE #3 Space debris tracking, G.Kirchner, F.Koidl, Graz August 2013 Range 2174 km targets distancesup to 3200 km targets cross section min 0.3 m 2 effective return quote 0.3 … 26 % ranging precision 0.3 … 4 m

11. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Germanium SPAD Detector Package for 1540 nm, 1994 - n Ge SPAD, 100 um / 77 K n PDE 2 - 5% @ 1540 nm n dark count >= 1 MHz n SLR and space debris LR @ 1540 nm demonstrated: CRL Tokyo, EOS Australia at Mt. Stromlo 250 mm H.Kunimori et al, Journal of Optics, Pure and Applied Optics, No.2 (2000), p1-4 I.Procházka et al, Optics Letters, Vol.21 (17), September 1, (1996), p 1375-1377

12. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 InGaAs/InP Photon Detectors Fujitsu, ø 30 μm FPD5W1KS n Wavelength range VIS … 1550 nm n Active area60 um diameter max. n Detection efficiency> 15 % @ 1064 nm 13 % @ 1550 nm n Dark count rate< 25 kHz / - 60 C n InGaAs technology still in progress n candidate for 1064 nm operation in a near future Separate absorption multiplication APD S.Cova, NIST 2004, I.Procházka, Applied Optics, Vol 40, No 33, p.1-6, 2001

13. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Single Quantum superconducting nanowire single photon detectors Sensitive from UV to MIR High efficiency for NIR: >75% for 1310nm,>70% 1550nm Short dead time: 5-10 ns High time resolution: < 50 ps time jitter Low noise: tunable dark countrate 1-100 Hz Small size 10 (50 ?) um diameter only G. Bulgarini, Val Zviler, Single Quantum BV, Lorentzweg 1, 2628CJ Delft, Netherlands

14. I.Prochazka et al, Laser solutions for Orbital Space Debris. Université Paris Diderot, 2015 Conclusion n Photon counting is the only receiver option for laser ranging to orbiting space debris. n SPADs based on Si provide good detection efficiency at 532 nm, existing, available, heritage n SPADs based on InGaAs are promising candidates for 1064 nm range, energy budget IF available n Supeconducting detectors are a dream for future systems operating at 1540 nm, energy budget, eye safety IF available n Good News -Europe is a leader in developing these detectors n We should not miss this chance ! n Thanks for your attention