Semiconductor laser based, injection locking maintaining broad linewidth generated by a direct current modulation of a master laser

Abstract

Semiconductor laser based, injection locking was performed for efficient excitation of subjects. The linewidth of the master laser was extended to 380MHz by using a frequency modulation technique through a direct current modulation. By the injection locking technique with a broad-area semiconductor laser, the frequency modulated input was amplified to 610mW, faithfully maintaining the broadened linewidth and the spectral shape. This result means that a compact high power laser system is possible with broad linewidth that is precisely controllable.

Stabilization and time resolved measurement of the frequency evolution of a modulated diode laser for chirped pulse generation

“…Current modulation causes both intensity and frequency modulation. Intensity modulation can be alleviated by injection locking of a separate laser with the modulated light [25,26], where the slave laser reproduces the frequency modulation only.…”

Opto-Electronics Review

“…An effective approach to produce a high-quality, highpower beam is to separate the generation of the spectrally narrow and diffraction limited beam from its amplification. There are three basic schemes that use semiconductor gain devices [68]: (i) resonant amplification by the optical injection-locking (OIL) [69,70], (ii) double-pass amplification in the BAL (with an AR-coated front facet and seed injected at a small angle [71,72], and (iii) travelling-wave amplification in the TA (with both facets quality AR-coated) [68,[73][74][75][76][77]. The two latter schemes are known as the master oscillator power amplifier (MOPA).…”