Stereopsis-Inspired Time-Stretched Amplified Real-Time Spectrometer (STARS)

Abstract

We introduce and demonstrate a single-shot real-time optical vector spectrum analyzer (VSA). This simple and powerful instrument combines amplified dispersive Fourier transform with stereopsis reconstruction algorithm and is inspired by binocular vision in biological eyes. Moreover, a dynamic time-stretch concept is employed to dramatically enhance the phase reconstruction accuracy and dynamic range for ultrashort optical signals (>; 30 times). We show that, using a noniterative analytical expression, the phase profile of the input signal can be reconstructed using intensity-only measurements. The proposed method is experimentally proved by fully characterizing the time-varying amplitude and phase of single-shot THz-bandwidth optical signals, with durations ranging from sub-ps to 35 000 ps, with ultrasmall to ultralarge temporal phase variations and at 25-MHz update rate. We have also used this instrument to characterize the amplitude and phase of a prechirped 40-Gbps DQPSK optical signal using a 1.5-GHz digitizer and without using a reference signal.