Journal: Scientific Reports

Article Title: Subcarrier wave continuous variable quantum key distribution with discrete modulation: mathematical model and finite-key analysis

doi: 10.1038/s41598-020-66948-0

Figure Lengend Snippet: Principal scheme of SCW CV-QKD setup. PSM is an electro-optical phase modulator; VOA is a variable optical attenuator; SF is a spectral filter that cuts off the carrier; PD is a photodiode. Diagrams in circles show the absolute value of signal spectrum taking into account only the first-order subcarriers. Diagrams in squares illustrate the absolute value of signal spectrum and comparison of spectra for various phase shifts; different coherent states are shown on phase plane.

Article Snippet: PSM is an electro-optical phase modulator; VOA is a variable optical attenuator; SF is a spectral filter that cuts off the carrier; PD is a photodiode.

Techniques: Comparison

Journal: Nature Communications

Article Title: Nonlinear optical components for all-optical probabilistic graphical model

doi: 10.1038/s41467-018-04578-x

Figure Lengend Snippet: Simulation and experimental results of normalization. a Experimental setup to normalize two powers A and B . The pump sources are two mode-locked fiber lasers. The characteristics of these lasers are as follows: λ A = 1559 nm with 8 MHz repetition rate and 200 fs pulse width, and the other one λ B = 1557 nm, 109 MHz, and 240 fs pulse width. The probe was a continuous wave (CW) diode laser λ probe = 1480 nm. Three variable optical attenuators (VOAs) and two beam splitters (BS1 and BS2) were used to monitor input powers to saturable absorbers (SAs). The polarization beam combiners (PBCs) were also used to combine the pump lasers powers with probe laser power with preserving their polarization. And a wavelength-division multiplexing (WDM) device was used in order to separate the modulated probe laser from the modulated pump lasers (see Methods for detail). b Simulated result to normalize two numbers A and B where we assume B is constant. c Experimental result to normalize two powers. In both b , c , the feedback-loop system adjusts the modulated power of C ′ + D ′ to remain constant

Article Snippet: Three variable optical attenuators (VOAs) and two beam splitters (BS1 and BS2) were used to monitor input powers to saturable absorbers (SAs).

Techniques: Preserving, Multiplexing