Modular, high energy, widely-tunable ultrafast fiber source

• US 7,688,499 B2
• Filed: 12/22/2006
• Issued: 03/30/2010
• Est. Priority Date: 05/23/2000
• Status: Expired due to Fees

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: Galvanauskas, Almantas, Harter, Donald J., Fermann, Martin E.
• Primary Examiner(s): Hellner; Mark
• Assistant Examiner(s): Diacou; Ari M
• Application Number:
  US11/643,765
• Publication Number:
  US 20070103765A1
• Time in Patent Office: 1,194 Days
• Field of Search: None
• US Class Current: 359/337.5
• 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 3/0675 Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/094019 Side pumped fibre, whereby pump light is coupled laterally into the fibre via an optical component like a prism, or a grating, or via V-groove coupling
• CPC Class Codes: H01S 3/094042 of a fibre laser
• CPC Class Codes: H01S 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 3/1112 Passive mode locking
• CPC Class Codes: H01S 3/1115 using intracavity saturable absorbers
• CPC Class Codes: H01S 3/1616 thulium
• CPC Class Codes: H01S 3/1618 ytterbium
• CPC Class Codes: H01S 3/302 in an optical fibre

Abstract

A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Modularity is ensured by the implementation of interchangeable amplifier components. System compactness is ensured by employing efficient fiber amplifiers, directly or indirectly pumped by diode lasers. Dispersive broadening is introduced by dispersive pulse stretching in the presence of self-phase modulation and gain, resulting in the formation of high-power parabolic pulses. In addition, dispersive broadening is also introduced by simple fiber delay lines or chirped fiber gratings, resulting in a further increase of the energy handling ability of the fiber amplifiers. After amplification, the dispersively stretched pulses can be re-compressed to nearly their bandwidth limit by the implementation of another set of dispersive delay lines. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used.

Claims

1. An optical pulse source comprising,

a seed laser;

a Yb;

fiber amplifier for amplifying pulses generated by said seed laser, said fiber amplifier generating amplified pulses;

an optical fiber configured to receive said amplified pulses, said optical fiber subjecting said amplified pulses to large levels of self-phase modulation that broadens the pulse width of said received amplified pulses.

2. An optical pulse source according to claim 1, where said seed laser is a modelocked fiber laser.

3. An optical pulse source according to claim 1, where said seed laser is a modelocked Yb:

fiber laser.

9. An optical pulse source according to claim 1, wherein said seed laser comprises a fiber seed laser.

10. An optical pulse source according to claim 1, wherein both said seed laser and said Yb:

amplifier are diode pumped.

4. An optical system, comprising:

a pulse source comprising a mode-locked Yb;

fiber seed laser;

a high power Yb;

fiber amplifier for amplifying pulses generated by said seed laser; and

an optical fiber configured to have said high power amplifier as an input, and subjecting pulses amplified by said high power amplifier to large levels of self-phase modulation.

5. An optical pulse source comprising:

a seed laser;

a Yb;

fiber amplifier having a core diameter in the range of about 1 μ

m to 50 μ

m, and configured in such a way that the fundamental mode is excited and propagates in said Yb;

amplifier, said Yb;

amplifier generating amplified pulses;

an optical fiber configured to receive said amplified pulses, said optical fiber subjecting said amplified pulses to large levels of self-phase modulation.

6. An optical pulse source according to claim 5, wherein a length of said amplifier is in the range of about 1 m-5 m.

7. An optical pulse source according to claim 5, wherein said amplifier comprises a Yb:

dopant concentration of about 2.5 mole %.

8. An optical pulse source according to claim 5, wherein said fiber amplifier is configured as a parabolic pulse amplifier.