Fiber laser arrangement with regenerative pulse amplification

• US 20080225386A1
• Filed: 11/26/2007
• Published: 09/18/2008
• Est. Priority Date: 11/27/2006
• Status: Abandoned Application

• Current Assignee: Jenoptik Laser, Optik, Systeme GmbH (Jenoptik AG)
• Original Assignee: Jenoptik Laser, Optik, Systeme GmbH (Jenoptik AG)
• Inventors: Leitner, Martin
• Application Number:
  US11/986,761
• Publication Number:
  US 20080225386A1
• Time in Patent Office: Days
• US Class Current: 359/348
• CPC Class Codes: H01S 3/0057 Temporal shaping, e.g. pulse compression, frequency chirping soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108
• CPC Class Codes: H01S 3/0604 in the form of a plate or disc
• CPC Class Codes: H01S 3/067 Fibre lasers
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/094084 with pump light recycling, i.e. with reinjection of the unused pump light, e.g. by reflectors or circulators
• CPC Class Codes: H01S 3/1618 ytterbium
• CPC Class Codes: H01S 3/1675 titanate, germanate, molybdate, tungstate
• CPC Class Codes: H01S 3/2316 Cascaded amplifiers
• CPC Class Codes: H01S 3/235 Regenerative amplifiers

Abstract

A fiber laser arrangement with regenerative pulse amplification, having a femtosecond fiber oscillator as a pulse-generating unit, a fiber amplifier designed both as a pulse-amplifying and pulse-stretching device to amplify and to stretch the femtosecond pulses generated by the femtosecond fiber oscillator, a regenerative amplifier, which has a disk-shaped laser crystal as a gain medium, and which is designed to produce additional pulse stretching during the regenerative amplification, and a pulse compression device, which temporally compresses the amplified and time-stretched pulses.

Claims

1. A fiber laser arrangement with regenerative pulse amplification, comprising:

a femtosecond fiber oscillator as a pulse-generating unit;

a fiber amplifier designed both as a pulse-amplifying and pulse-stretching device to amplify and to stretch femtosecond pulses generated by the femtosecond fiber oscillator;

a regenerative amplifier, which has a disk-shaped laser crystal as a gain medium, and which is designed to produce additional pulse stretching during regenerative amplification; and

a pulse compression device, which temporally compresses the amplified and time-stretched pulses.

2. The fiber laser arrangement according to claim 1, wherein the fiber amplifier has an amplifying fiber with a fiber length in a range of 2-10 m and a material dispersion of 15-30 fs²/mm.

3. The fiber laser arrangement according to claim 2, wherein crystal material is present in the regenerative amplifier, the crystal material being designed to serve as a path along which the pulse travels for further pulse stretching.

4. The fiber laser arrangement according to claim 3, wherein the disk-shaped laser crystal consists of a material with an amplification bandwidth which is narrower than the bandwidth of the femtosecond pulses generated by the femtosecond fiber oscillator.

5. The fiber laser arrangement according to claim 4, wherein the bandwidth ratio between the spectral bandwidth of the fiber-generated femtosecond pulses and the amplification bandwidth of the disk-shaped laser crystal is in a range of 1.2-2.

6. The fiber laser arrangement according to claim 5, wherein the regenerative amplifier contains a laser crystal designed as a 100-300-μ

m-thick Yb;

KYW disk with doping in a range of 5-15%.

7. The fiber laser arrangement according to claim 6, wherein the femtosecond fiber oscillator is designed to emit a central wavelength which lies at a point of maximum amplification of the regenerative amplifier.

8. The fiber laser arrangement according to claim 6, wherein the femtosecond fiber oscillator is designed to generate femtosecond pulses which are no more than ⅕

of their spectral width away from a point of maximum amplification of the regenerative amplifier.

9. The fiber laser arrangement according to claim 1, wherein the femtosecond fiber oscillator and the fiber amplifier form a monolithic unit.

10. The fiber laser arrangement according to claim 1, and further comprising a fast electro-optic switch serving as a pulse picker device provided between the fiber amplifier and the regenerative amplifier to couple preamplified and stretched pulses into the regenerative amplifier.

11. A process for generating regeneratively amplified femtosecond pulses by means of a fiber laser arrangement with regenerative pulse amplification, the laser arrangement including a femtosecond fiber oscillator as a pulse-generating unit, a fiber amplifier designed both as a pulse-amplifying and pulse-stretching device to amplify and to stretch femtosecond pulses generated by the femtosecond fiber oscillator, a regenerative amplifier, which has a disk-shaped laser crystal as a gain medium, and which is designed to produce additional pulse stretching during regenerative amplification, and a pulse compression device, which temporally compresses the amplified and time-stretched pulses, the process comprising stretching the femtosecond pulses to be regeneratively amplified by means of the fiber amplifier and by crystal material in the regenerative amplifier.

12. The process according to claim 11, wherein the pulse stretching is carried out with an overall stretching factor of no more than 200.