Supercontinuum pulse source

• US 8,718,104 B2
• Filed: 03/10/2013
• Issued: 05/06/2014
• Est. Priority Date: 01/19/2008
• Status: Active Grant

• Current Assignee: NKT Photonics A/S (Hamamatsu Photonics KK)
• Original Assignee: Fianium Ltd (Hamamatsu Photonics KK)
• Inventors: Clowes, John Redvers, Grudinin, Anatoly Borisovich, Godfrey, Ian Michael
• Primary Examiner(s): Niu, Xinning
• Application Number:
  US13/792,179
• Publication Number:
  US 20130208739A1
• Time in Patent Office: 422 Days
• Field of Search: 372/21
• US Class Current: 372/21
• CPC Class Codes: G01N 2021/6419 Excitation at two or more wavelengths
• CPC Class Codes: G01N 2021/6441 with two or more labels
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: G01N 2201/0697 Pulsed lasers
• CPC Class Codes: G02B 21/16 adapted for ultraviolet illumination ; Fluorescence microscopes G02B21/0076 takes precedence
• CPC Class Codes: G02F 1/3528 for producing a supercontinuum
• CPC Class Codes: G02F 1/353 Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams
• CPC Class Codes: G02F 1/365 in an optical waveguide structure G02F1/377, G02F1/395 take precedence
• CPC Class Codes: H01S 3/0085 Modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 3/0092 Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity nonlinear frequency conversion per se G02F1/35
• CPC Class Codes: H01S 3/10 Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
• CPC Class Codes: H01S 3/10046 Pulse repetition rate control H01S3/11 takes precedence
• CPC Class Codes: H01S 3/1024 for pulse generation
• CPC Class Codes: H01S 3/108 using non-linear optical devices, e.g. exhibiting Brillouin or Raman scattering mode locking using a non-linear element H01S3/1112
• CPC Class Codes: H01S 3/1106 Mode locking
• CPC Class Codes: H01S 3/2308 Amplifier arrangements, e.g. MOPA

Abstract

An optical pulse source for generating optical supercontinuum pulses comprises an optical pump laser operable to generate optical pump pulses at a pump pulse repetition rate Rf; a nonlinear optical element comprising an optical fiber for generating optical supercontinuum pulses; an optical modulator operable to selectively control the launch of pump pulses into the optical fiber at a reduced, lower repetition rate Rr=Rf/N in order to generate optical supercontinuum pulses at a selectable and lower repetition rate; an optical fiber amplifier located between the optical modulator and the optical pump laser; wherein the optical supercontinuum pulses generated by the optical fiber have a supercontinuum spanning from below 450 nm to greater than 2000 nm; wherein the optical pulse source is provided with a microprocessor configured to determine when supercontinuum pulses are delivered; and wherein the optical pulse source is configured to provide an output trigger signal.

Claims

1. Optical pulse source for generating optical supercontinuum pulses, comprising:

an optical pump laser operable to generate optical pump pulses at a pump pulse repetition rate Rf;

a nonlinear optical element comprising an optical fiber arranged to receive the optical pump pulses and configured to generate therefrom optical supercontinuum pulses;

an optical modulator provided between the pump laser and the optical fiber and operable to selectively control the launch of pump pulses into the optical fiber at a reduced, lower repetition rate Rr=Rf/N, wherein N is a positive integer, in order to generate optical supercontinuum pulses at a selectable repetition rate lower than the pump pulse repetition rate;

an optical fiber amplifier located between the optical modulator and the optical pump laser;

wherein the optical pulse source is configured such that the optical supercontinuum pulses generated by the optical fiber have a supercontinuum spanning from below 450 nm to greater than 2000 nm;

wherein the optical pulse source is provided with a microprocessor configured to determine when supercontinuum pulses are delivered; and

wherein the optical pulse source is configured to provide an output trigger signal.

2. The optical pulse source of claim 1 wherein the optical pulse source further comprises a wavelength tunable optical bandpass filter configured to receive an optical supercontinuum pulse and to wavelength filter the pulse at a predetermined wavelength.

3. The optical pulse source of claim 1 wherein the optical pulse source comprises an all-fiber source wherein said optical pump laser comprises a fiber oscillator, said optical modulator comprises a fiber coupled optical modulator, and wherein the optical pulse source is configured such that pump pulses are launched into said fiber without free space optics.

4. The optical pulse source according to claim 2 wherein the wavelength tunable optical bandpass filter comprises an acousto-optic tunable filter.

5. The optical pulse source according to claim 1 wherein said optical modulator comprises an acousto-optic modulator.

6. The optical pulse source of claim 1 configured to generate optical supercontinuum pulses at pulse repetition rates variable between 40 MHz and less than 100 kHz.

7. The optical pulse source according to claim 1, wherein the optical pulse source further comprises a gating device provided after the nonlinear optical element and configured to receive and pulse-pick optical supercontinuum pulses.

8. The optical pulse source according to claim 6 wherein pump pulses are launched into said optical fiber without the use of free space optics.

9. The optical pulse source according to claim 1 comprising a second optical fiber amplifier located between said optical modulator and said nonlinear optical element.

10. The optical pulse source according to claim 9 wherein pump pulses are launched into said optical fiber without the use of free space optics.

11. The optical pulse source according to claim 1 wherein pump pulses are launched into said optical fiber without the use of free space optics.

12. Optical pulse source for generating optical supercontinuum pulses, comprising:

an optical pump laser operable to generate optical pump pulses at a pump pulse repetition rate Rf;

a nonlinear optical element comprising an optical fiber arranged to receive the optical pump pulses and configured to generate therefrom optical supercontinuum pulses;

an optical modulator provided between the pump laser and the optical fiber and operable to selectively control the launch of pump pulses into the optical fiber at a reduced, lower repetition rate Rr=Rf/N, wherein N is a positive integer, in order to generate optical supercontinuum pulses at a selectable repetition rate lower than the pump pulse repetition rate;

wherein the optical pulse source is configured such that the optical supercontinuum pulses generated by the optical fiber have a supercontinuum spanning from below 450 nm to greater than 2000 nm;

wherein the optical pulse source is provided with a microprocessor configured to determine when supercontinuum pulses are delivered by the optical pulse source; and

wherein the optical pulse source is configured to provide an output trigger signal.

13. The optical pulse source according to claim 12 wherein pump pulses are launched into said optical fiber without the use of free space optics.

14. The optical pulse source of claim 13 wherein the optical pulse source further comprises a wavelength tunable optical bandpass filter configured to receive an optical supercontinuum pulse and to wavelength filter the pulse at a predetermined wavelength.

15. The optical pulse source of claim 12 wherein the optical pulse source further comprises a wavelength tunable optical bandpass filter configured to receive an optical supercontinuum pulse and to wavelength filter the pulse at a predetermined wavelength.

16. The optical pulse source according to claim 12 comprising an optical fiber amplifier located between said optical modulator and said nonlinear optical element.