Title :
Passive Mode-Locking of a Ti : Sapphire Laser by InGaP Quantum-Dot Saturable Absorber
Author :
Savitski, Vasili G. ; Schlosser, Peter J. ; Hastie, Jennifer E. ; Krysa, Andrey B. ; Roberts, John S. ; Dawson, Martin D. ; Burns, David ; Calvez, Stephane
Author_Institution :
Inst. of Photonics, Univ. of Strathclyde, Glasgow, UK
Abstract :
We demonstrate the use of a novel InGaP quantum-dot (QD) saturable absorber (SA) to induce passively mode-locked (ML) operation of a Ti : sapphire laser. Pulses as short as 518 fs are obtained at 752 nm with an average output power of up to 190 mW for 2.3 W of absorbed pump power at 532 nm. The absorption recovery of the SA is characterized by two decay coefficients: a fast and a slow component having time constants of 0.4 and 300 ps, respectively. The saturation fluence of the InGaP QDs was measured to be 28 ??J/cm2, the initial low-signal absorption was 1.5%, where 1.15% was nonsaturable loss.
Keywords :
III-V semiconductors; gallium compounds; indium compounds; laser mirrors; laser mode locking; optical losses; optical pulse generation; optical pumping; optical saturable absorption; sapphire; semiconductor quantum dots; solid lasers; titanium; Al2O3:Ti; InGaP; SESAM; Ti :sapphire laser; absorption recovery; decay coefficients; low-signal absorption; nonsaturable loss; passive mode locking; power 2.3 W; quantum dot saturable absorber; saturation fluence; semiconductor saturable absorber mirror; time 0.4 ps; time 300 ps; time 518 fs; wavelength 532 nm; wavelength 752 nm; Laser absorbers; mode-locked (ML) laser; spectroscopy; ultrafast optics;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2009.2037599
