Pulse control of frequency and width for a real-time independently adjustable laser source

Abstract

A set of semiconductor laser pulse seed sources based on an embedded chip is proposed. The greatest feature is that the optical pulse frequency and width can be independently adjusted in real time. The pulse seed sources can be switched independently and online from the gain-switched mode to the quasi-continuous wave mode to obtain optimal optical parameters for specific applications. To explore the physical mechanism of the semiconductor laser source, the rate equation that describes the carrier-photon transient change in a semiconductor laser cavity is numerically derived and solved. Subsequently, problems that need to be considered while designing the drive circuit are identified. The system evaluation indicates that the optical pulse frequency adjustment range is 250 Hz to 42 MHz, and the narrowest optical pulse output width is 80 ps. The pulse seed source can drive semiconductor lasers with different central wavelengths (1064, 1550, and 1970 nm), and can also simultaneously drive two semiconductor lasers and output dual-band optical pulses. It can be used as a seed source for general high-power optical systems, and exhibits good application value and extensive market prospects.