Chirped-pulse oscillators for the generation of high-energy femtosecond laser pulses

• Published in: Laser and particle beams Vol. 23; no. 2; pp. 113 - 116
• Main Authors: FUERBACH, ALEXANDER, FERNANDEZ, A., APOLONSKI, A., FUJI, T., KRAUSZ, F.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.06.2005
• Subjects: Ablation Field; Femtosecond; Femtosecond laser; Femtosecond pulsed lasers; Femtosecond pulses; Lasers; Micromachining; Mirrors; Oscillators; Ultrafast; X-rays; Femtosecond; Femtosecond laser; Ultrafast; Ablation Field; Micromachining
• ISSN: 0263-0346; 1469-803X
• DOI: 10.1017/S0263034605050196

This paper reports on a novel approach for producing high energy femtosecond pulses without external amplification. The so-called chirped-pulse oscillator (CPO) concept is based on an extended-cavity oscillator, operating at small net positive intracavity group delay dispersion (GDD), over a broad spectral range by the use of chirped multilayer mirrors. The resultant chirped picosecond pulses are compressed by a dispersive delay line external to the laser cavity. Utilizing this technique, sub-30 fs pulses with an energy exceeding 200 nJ at a repetition rate of 11 MHz were produced. The demonstrated peak power in excess of 5 MW is the highest ever achieved from a cw-pumped laser and is expected to be scaleable to tens of megawatts by increasing the pump power and/or decreasing the repetition rate. The demonstrated source allows micromachining of any materials under relaxed focusing conditions.