A background-free phase-coded microwave pulse generator by optoelectronic oscillation

Abstract

We propose and demonstrate a photonic scheme to generate background-free binary phase-coded microwave pulses based on optoelectronic oscillation (OEO). The significant merit of our pulse generator is that an external microwave source which is always essential in previous works is no more required. The binary phase-coded microwave pulse is directly generated by truncating an OEO signal into pulses. Moreover, only a single modulator is used in our system which performs two important functions. One is the construction of OEO loop, the other is the phase-coding of microwave pulses. Since only the phase of optical signal is modulated, the phase-coded microwave pulses are free from baseband frequency components. The proposed scheme is theoretically analyzed and experimentally verified.