Generation of tunable single-mode picosecond pulses from an AlGaAs semiconductor laser with grating feedback

Abstract

Widely tunable single-mode picosecond pulses have been obtained from a buried optical guide AlGaAs semiconductor laser operated with external grating feedback. Intensity autocorrelation measurements show single-mode 30-ps pulses. A tuning range of 20 nm, corresponding to more than 70 different laser frequencies, was easily achieved.

Nonresonant self-injection seeding of a gain-switched diode laser

“…There are two significant differences between our results and those reported earlier for the well-known technique of self-seeding in gain-switched lasers (see, e.g., [5]- [8] and references therein). First, we only observed the spectral narrowing under nonresonant operation, when the round-trip period of the external cavity was significantly detuned from the modulation period.…”

“…To explain these results, we note that the external cavity length in our case is several (at least 2-3) orders of magnitude smaller (and the external-cavity round-trip frequency therefore greater by the same factor) than that typically used in the cavity configuration described in [5]- [8]. It has been shown [6], [7] that a timing detuning between the seeding and lasing pulses, within a certain window of the order of several tens of picoseconds, is required for successful self-seeding.…”

Tunable operation of a gain-switched diode laser by nonresonant self-injection seeding

“…spectrum was reproducible, and much more stable than that observed in continuous-wave (CW) operation. There are two significant differences between our results and those reported earlier for the well-known technique of self-seeding in gain-switched lasers [4]- [6]. First, we only observed the spectral narrowing under nonresonant operation, i.e., when the round-trip period of the external cavity was significantly detuned from the modulation period.…”

Detailed Comparison of Injection-Seeded and Self-Seeded Performance of a 1060-nm Gain-Switched Fabry–PÉrot Laser Diode

“…For this reason, it is important to establish whether self seeding leads to any degradation of performance compared to injection seeding. Whilst previous studies have been made on either externally seeded systems [18]- [20], or on self-seeded systems [21]- [28], and the general conclusions have been that similar performance can be achieved from both seeding approaches, as far as we are aware, no systematic comparison of the relative performance of the two approaches using the same diode appears to have been previously published. Moreover, no detailed study of the pulse shapes obtained using a complete pulse characterization technique (providing both phase and amplitude profiles-in our case using a recently developed linear frequency resolved optical grating (FROG) technique [29]) has previously been provided.…”

“…In a FP cavity diode, this is essential in order to obtain good spectral quality output (i.e., lasing on a single longitudinal cavity mode [18], [21]), and provides timing jitter reduction in both DFB and FP gain-switched systems [6], [9].…”