PSK homodyne receiver sensitivity measurements at 1.5 μm

PSK Homodyne Experiment using a DFB Laser at 1.3 μm

“…For example the received power required for a BER of 10" 8 in a PSK experiment [3] is -64 dBm, whereas in our case, the error rate achieved at -33 dBm is 10" 7 . We attribute our poor receiver sensitivity to the following factors:…”

“…On the other hand, an experiment using a single light source for PSK homodyne detection has been reported as early as 1983 [3]. In [3], the light source used was an HeNe gas laser.…”

“…In [3], the light source used was an HeNe gas laser. Recent advances in the device and component technology have seen the development of distributed feedback (DFB) laser diodes and the use of a lithiumniobate crystal with a Titanium diffused waveguide as a phase modulator.…”

Upper Bounds on the Performance of the MPSK and Differentially Encoded MPSK Coherent Optical Systems Impaired by Laser Phase Noise

“…(i-l)T s <t<iT s (1) where co, F = -; k any integer, dj takes on {(21 -1) π/ 's M; 1 = 0, l, 2,..., M -1} with equal probabilities for the MPSK as well as the differentially encoded MPSK signaling, W(t) = Wj (t) -W 2 (t) is a Wiener process that accounts for the phase instabilities in the local as well as transmitter lasers, Ψ is a random phase uniformly distributed on [π, -π], and n (t) represents the combined shot noise of the local oscillator and additive circuitry noise modeled as a white Gaussian noise (AWON). In the sequel, we consider the shot noise to be the dominant factor and the photodetector dark current as well as the additive circuit noise have little or no impact on the performance of the system.…”

“…ment in receiver sensitivity of up to 20 dB when compared with the intensity modulated systems utilizing direct detection techniques [1][2][3]. Since the carrier signal for an optical system is in the optical domain, in this paper, we choose to refer to the carrier at the Intermediate Frequency (IF) range as the subcarrier signal.…”