Resonant Fabry-Perot semiconductor saturable absorbers and two photon absorption power limiters

• US 7,453,913 B2
• Filed: 08/05/2005
• Issued: 11/18/2008
• Est. Priority Date: 09/08/1998
• Status: Expired due to Fees

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: Harter, Donald J., Fermann, Martin E., Sucha, Gregg D., Jiang, Min
• Primary Examiner(s): Nguyen; Dung T
• Application Number:
  US11/197,852
• Publication Number:
  US 20050286569A1
• Time in Patent Office: 1,201 Days
• Field of Search: 372/18
• US Class Current: 372/18
• CPC Class Codes: G02F 1/3523 Non-linear absorption changing by light, e.g. bleaching
• CPC Class Codes: H01S 3/067 Fibre lasers
• CPC Class Codes: H01S 3/08059 Constructional details of the reflector, e.g. shape mirrors in general G02B5/08; mountings for mirrors G02B7/18
• CPC Class Codes: H01S 3/094003 the pumped medium being a fibre
• CPC Class Codes: H01S 3/1063 using a solid state device provided with at least one potential jump barrier
• CPC Class Codes: H01S 3/1118 Semiconductor saturable absorbers, e.g. semiconductor saturable absorber mirrors [SESAMs]; Solid-state saturable absorbers, e.g. carbon nanotube [CNT] based
• CPC Class Codes: H01S 3/1608 erbium

Abstract

An intracavity resonant Fabry-Perot saturable absorber (R-FPSA) induces modelocking in a laser such as a fiber laser. An optical limiter such as a two photon absorber (TPA) can be used in conjunction with the R-FPSA, so that Q-switching is inhibited, resulting in laser output that is cw modelocked. By using both an R-FPSA and a TPA, the Q-switched modelocked behavior of a fiber laser is observed to evolve into cw modelocking.

Claims

1. A method of generating cw mode-locked laser energy, comprising:

generating Q-switched modelocking pulses, and

automatically evolving cw modelocking from said Q-switched modelocking pulses.

2. The method of generating cw mode-locked laser energy, as defined in claim 1, wherein said evolving step comprises suppressing Q-switched modelocking.

3. The method of generating cw mode-locked laser energy, as defined in claim 1, wherein said evolving step comprises absorbing Q-switched laser pulses.

4. The method of generating cw mode-locked laser energy, as defined in claim 3, wherein said absorbing step comprises two photon absorption.

5. The method of generating cw mode-locked laser energy, as defined in claim 1, wherein said evolving step comprises temporally evolving cw modelocking from Q-switched modelocking.

6. The method of generating cw mode-locked laser energy, as defined in claim 5, wherein said temporally evolving step comprises making a transition from Q-switched modelocking to cw modelocking.

7. The method of generating cw mode-locked laser energy, as defined in claim 1, wherein said evolving step comprises pumping a gain medium in a laser cavity at a substantially constant input pump power.

8. A method of generating cw mode-locked laser energy, comprising:

generating Q-switched mode locked pulses to yield cw mode-locked laser pulses, and suppressing said Q-switched mode locked pulses.

9. A method of generating cw mode-locked laser energy, as defined in claim 8, wherein said suppressing step comprises two photon absorption.