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

Volume

22

Issue

4

fYear

2010

Firstpage

209

Lastpage

211

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;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2009.2037599

Filename

5373929