Title :
Characterization of Coupling Efficiency and Absorption Coefficient for Fiber-Coupled SNSPD With an Optical Cavity
Author :
Miki, Shigehito ; Yamashita, Taro ; Fujiwara, Mikio ; Sasaki, Masahide ; Wang, Zhen
Author_Institution :
Kobe Adv. Re search Center, Nat. Inst. of Inf. & Commun. Technol., Kobe, Japan
fDate :
6/1/2011 12:00:00 AM
Abstract :
We report the characterization of optical coupling efficiency and the absorption coefficient of fiber-coupled superconducting nanowire single photon detector with an optical cavity, which limit the system detection efficiency. The small lenses were applied to compact fiber-coupled package and the efficient optical coupling higher than 95% were confirmed experimentally. The absorption coefficient was also verified and reached to ~ 60% at 1550 nm wavelength and optimum polarized condition. The system detection efficiencies at 1550, 1310 and 810 nm were 28, 40 and 3%, respectively, which are related to the absorptance dependencies on wavelengths.
Keywords :
absorption coefficients; lenses; light polarisation; nanophotonics; nanowires; optical fibre couplers; superconducting photodetectors; absorption coefficient; compact fiber-coupled package; fiber-coupled SNSPD; fiber-coupled superconducting nanowire single photon detector; lenses; light polarization; optical cavity; optical coupling efficiency; system detection efficiency; wavelength 1310 nm; wavelength 1550 nm; wavelength 810 nm; Cavity resonators; Mirrors; Optical coupling; Optical fibers; Optical polarization; Optical variables measurement; NbN films; single photon detector; superconducting nanowire;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2010.2091486
