Abstract

We report generation of a cw train of optical pulse at terahertz repetition rate operating in the near infrared spectral region near 1.5 pm. The technique is based on a dual-frequency beat conversion in a nonlinear optical fiber.¹ In this technique, a dual frequency beat signal provides a periodical sinusoidal envelope. Reshaping half periods of the beat signal into pulses using a nonlinear process, a train of optical pulses can be generated with periodicity determined by the beat frequency. A number of mechanisms relaying on nonlinear propagation in optical fiber can be employed for this conversion. In particular, the Raman self-scattering or soliton self-frequency shift effect^2,3 can be employed for the generation of the train of femtosecond soliton pulses through optical beating.⁴ In this paper, we use this method for the generation of a cw train of 230 fs solitons at repetition rate 125 GHz, and then obtain a 1-THz pulse train using time-division multiplexing technique.

© 1994 Optical Society of America