On the quantum limit for optically preamplified receivers

Lê Nguyên Bình

Idelfonso Tafur Monroy

An optically preamplified receiver configuration resulting in a very low quantum limit is presented. Optical amplifiers are proven to efficiently enhance the receiver sensitivity of optical communication systems. We present an optically preamplified OOK/DD receiver scheme with a very low quantum limit, which is predicted to outperform previously studied configurations

Konrad Banaszek

Rasmus Larsson, Ruwan U. Weerasuriya, Peter A. Andrekson

Conventional optical amplifiers that use stimulated emission suffer from the generation of excess noise, thus limiting the performance in many applications. The phase-sensitive optical parametric amplifier, relying on the use of a nonlinear material for amplification, is an exception that can approach a noise figure of 0 dB. Its implementation in optical communication links has, however, been cumbersome due to increased complexity both in the transmitter and the receiver, effectively limiting the use of such amplifiers in practice. Here, we propose and demonstrate an implementation of a transmission system with exceptional performance in terms of receiver sensitivity (0.9 photons per bit) using a standalone ultralow-noise phase-sensitively preamplified receiver and a conventional single-wave optical transmitter. This is a significant simplification compared to previous demonstrations and can transform such amplifiers from a curiosity to practical use for example in deep-space-to-earth communication links.

Dmitry V Konarev, I. N. Matveev, S M Pshenichnikov

An equation for the distribution of the number of photoelectrons at the output of a radiation detector of an optical receiver with a preamplifier is derived for the case of a Poisson distribution of the incident photons. An analysis is given of the noise in a glass-fiber preamplifier. A computer calculation is reported of the probability of transmission of a signal for a given probability of spurious operation. This calculation is made for the case of an amplifier generating few modes. The results are given of an experimental investigation of a receiver with a neodymium glass-fiber amplifier. These results support the calculations.

Elanor H. Huntington