The technology demonstrates the use of a single-mode finite-linewidth se
miconductor laser with other homemade hardware and software for enabl
ing the single-photon quantum key distribution (QKD) and communicatio
n in the dense-wavelength division multiplexing (DWDM) passive optical
network (PON). All of the key components including the coherent single-p

hoton emitter, master-to-slave frequency/phase locking loop (F/PLL), self-
heterodyne-feedback single-mode-fiber 1-Bit-delay interferometric (DI), s

ingle-photon avalanche photodetector (SPAD), differential phase-shift-ke
ying (DPSK) QKD protocol synthesizer and algorithm, the pulsed bit-strea
m data format generating circuitry, and the proto-type DWDM-POM will

be implemented for the integration of QKD system-on-chip with the fiber-
based optical quantum communication (OQC) system from engineering vi

ewpoints. Novel technologies including self-heterodyne interferometric ul

tra-narrow linewidth analyzer, mutual master-to-slave phase/frequency lo
cking loop, high-Q-factor notch filtering with micro-cavity or Mach-Zehn

der/Fano resonant waveguide, and the simulated 25-100-km short-/long-
reach single-mode fiber network architecture will be established to facilita

te the transmission and characterization of the QKD embedded optical car
rier synthesized with all devices delivered by other sub-projects for 2-D/3-
D dense wavelength division multiplexing (DWDM) QKD/OQC in metropo
litan and backbone network applications. All the developed key compone
nts can be immediately used for on-chip integration and for systematic im
plementation of the single-photon QKD and OQC in the commercially avai
lable DWDM-PON. For the OQC beyond 10 Gbit/s, new data format trans
mission such as the QAM-OFDM-OQC for beyond 25 Gbit/s per WDM cha
nnel in combination with the DPSK-QKD stream as the cyclic prefix will be
performed by employing an advanced data synthesis algorithm.