Low-loss GaInNAs saturable absorber mode locking a 1.3-μm solid-state laser

Abstract

We have demonstrated stable self-starting passive cw mode locking of a solid-state laser at about 1.3 μm using a GaInNAs semiconductor saturable absorber mirror (SESAM). GaInNAs SESAMs show negligible nonsaturable losses, low saturation fluences (11 μJ/cm2) and picosecond decay times which make them well-suited for self-starting and stable cw mode locking. Sub-10-ps pulses were produced with a Nd:YLF laser at 1314 nm. The incorporation of about 2% nitrogen into InGaAs redshifts the absorption edge above 1330 nm and reduces the strain in the saturable absorber grown on a GaAs/AlAs Bragg mirror. Final absorption edge adjustments have been made with thermal annealing which blueshifts the absorption edge.

Solid-State Laser Mode-Locking Near 1.25 μm Employing a Carbon Nanotube Saturable Absorber Mirror

“…Other important parameters for passive mode-locking such as modulation depth (ΔR = 0.37%) and saturation fluence (Fsat = 6.0 µJ/cm 2 ) were also investigated by nonlinear reflection measurements. These optical characteristics of SWCNT-SAM compare favourably with those of previously reported SESAMs for ultrafast mode-locking [14,15].…”

Carbon nanotubes for ultrafast fibre lasers

“…for a wavelength band longer than 1.3 μm, a higher indium concentration is required. In its turn, a high indium concentration gives a rise to highly strained layers on GaAs-based Bragg mirrors and, therefore, decreases the quality of the surface and increases non-saturable losses [29]. Thus, new materials with strong ultrafast optical nonlinearities, broad-operating spectral range, simple processing and device packaging are still in high demand.…”

LT-InGaAs Layer Grown for Near Surface SESAM Application

“…• C [5,6]. It allows to assume that both As 0 Ga defects and the precipitations occur in the QW material grown under As excess conditions.…”