Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE
Ultra-sensitive NIR-spectrometer based on frequency up-conversion detector
Lijun Ma, Oliver Slattery, Xiao Hong Tang
Abstract
We developed a spectrometer for signals at single photon levels in the near infrared (NIR) region based on a tunable up-conversion detector. This detector uses a 5-cm periodically poled lithium niobate (PPLN) waveguide to convert NIR photons to a shorter wavelength that are then detected by a silicon avalanche photodiode. The sensitivity of this spectrometer is -126 dBm, which is three orders-of-magnitude higher than any commercial optical spectrum analyzer in this wavelength range. Additionally, we use two PPLN waveguides to implement a polarization-independent up-conversion spectrometer, and use it to study a fiber-based quantum communication system.