Chinese Optics Letters, 2021, 19 (7): 072701, Published Online: May. 20, 2021
Heterodyne detection enhanced by quantum correlation Download: 533次
Figures & Tables
Fig. 1. Schematics for heterodyne detection of light. (a) The signal mode enters into the detector together with an unexcited mode (image band vacuum) that gives rise to 3 dB heterodyne noise[4,5,7]. (b) Before being received by the detector, the signal light passes through a parametric amplifier where quantum correlation[17] is generated between the signal mode and the image band vacuum for reduction of the 3 dB heterodyne noise. ωs,i,l, angular frequency of the signal/image band/local oscillator mode; (t), quantum field of signal/amplified light beam; εl(+)(t), classical field of local oscillator light beam; 50-50, balanced beamsplitter; LA, linear amplifier; J−(t) ≡ J2(t) − J1(t), average differential photocurrent signal from the detector. Inset: a typical parametric amplifier consisting of a type-I periodically-poled KTiOPO4 (PPKTP) crystal inside an optical cavity and a laser pump[20] may be used to realize the proposed heterodyne detection with ωp = ωs + ωi, where ωp is the pump angular frequency. M1 & M2, cavity mirrors; DM, dichromatic mirror.
Boya Xie, Sheng Feng. Heterodyne detection enhanced by quantum correlation[J]. Chinese Optics Letters, 2021, 19(7): 072701.