Variable repetition rate supercontinuum pulses

• US 10,074,957 B2
• Filed: 02/13/2017
• Issued: 09/11/2018
• Est. Priority Date: 01/19/2008
• Status: Active Grant

• Current Assignee: NKT Photonics A/S (Hamamatsu Photonics KK)
• Original Assignee: NKT Photonics A/S (Hamamatsu Photonics KK)
• Inventors: Clowes, John Redvers, Grudinin, Anatoly Borisovich, Godfrey, Ian Michael
• Primary Examiner(s): Niu, Xinning
• Application Number:
  US15/431,111
• Publication Number:
  US 20170250518A1
• Time in Patent Office: 575 Days
• 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

A method of providing optical supercontinuum pulses can comprise generating optical pump pulses with an optical pump laser, the optical pump pulses having a pump pulse repetition rate; launching optical pump pulses into a nonlinear optical element comprising an optical fiber; generating optical supercontinuum pulses from the optical pump pules via spectral broadening within the optical fiber; selectively providing a plurality of different repetition rates for the optical pump pulses so as to generate optical supercontinuum pulses having different repetition rates; and providing nominally identical spectral broadening of the optical supercontinuum pules having the different repetition rates.

Claims

1. A method of providing optical supercontinuum pulses, comprising:

generating optical pump pulses with an optical pump source;

launching optical pump pulses into a nonlinear optical element comprising an optical fiber;

generating optical supercontinuum pulses from the optical pump pulses via spectral broadening within the optical fiber;

selectively providing a plurality of different repetition rates for the optical pump pulses so as to generate optical supercontinuum pulses having different repetition rates; and

providing nominally identical spectral broadening of the optical pump pulses having the different repetition rates.

2. The method of providing optical supercontinuum pulses of claim 1, comprising using the optical supercontinuum pulses to provide illumination in an application to excite fluorescence.

3. The method of providing optical supercontinuum pulses of claim 2, comprising measuring a decay lifetime of the excited fluorescence.

4. The method of providing optical supercontinuum pulses of claim 2, wherein the application comprises fluorescence lifetime imaging microscopy (FLIM).

5. The method of providing optical supercontinuum pulses of claim 2, wherein the application comprises stimulated emission depletion (STED) microscopy.

6. The method of providing optical supercontinuum pulses of claim 1, comprising wavelength filtering the optical supercontinuum pulses at a predetermined wavelength.

7. The method of providing optical supercontinuum pulses of claim 1, comprising launching the optical pump pulses into the optical fiber without the use of free space optics.

8. The method of providing optical supercontinuum pulses of claim 1, comprising amplifying the optical pump pulses prior to launching the optical pump pulses into the nonlinear optical element.

9. The method of providing optical supercontinuum pulses of claim 8, wherein the amplified optical pump pulses have the plurality of different repetition rates prior to launching the amplified optical pump pulses into the nonlinear optical element.

10. A method of providing optical supercontinuum pulses, comprising:

generating optical pump pulses with an optical pump source, an optical pump pulse having a pulse energy;

launching optical pump pulses into a nonlinear optical element comprising an optical fiber;

generating optical supercontinuum pulses from the optical pump pulses via spectral broadening within the optical fiber;

selectively providing a plurality of different repetition rates for the optical pump pulses so as to generate optical supercontinuum pulses having different repetition rates; and

wherein the pulse energy is fixed as the pulse to pulse separation is increased with reducing repetition rate.

11. The method of providing optical supercontinuum pulses of claim 10, comprising using the optical supercontinuum pulses to provide illumination in an application to excite fluorescence.

12. The method of providing optical supercontinuum pulses of claim 11, comprising measuring a decay lifetime of the excited fluorescence.

13. The method of providing optical supercontinuum pulses of claim 11, wherein the application is fluorescence lifetime imaging microscopy (FLIM).

14. The method of providing optical supercontinuum pulses of claim 11, wherein the application is stimulated emission depletion (STED) microscopy.

15. The method of providing optical supercontinuum pulses of claim 10, comprising wavelength filtering the optical supercontinuum pulses at a predetermined wavelength.

16. The method of providing optical supercontinuum pulses of claim 10, comprising launching the optical pump pulses into the optical fiber without the use of free space optics.

17. The method of providing optical supercontinuum pulses of claim 10, comprising amplifying the optical pump pulses prior to launching the pump pulses into the nonlinear optical element.

18. A supercontinuum pulse source, comprising:

an optical pump source for generating optical pump pulses;

the optical pump pulses having a selectively variable pump pulse repetition rate so that optical pump pulses can have different repetition rates;

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

wherein the optical pump pulses having different repetition rates generate optical supercontinuum pulses having different repetition rates; and

wherein optical pump pulses having different repetition rates are nominally identically spectrally broadened by the nonlinear optical element.

19. A supercontinuum pulse source, comprising:

an optical pump source operable to generate optical pump pulses, an optical pump pulse having a pump pulse energy;

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

the optical pump pulses further comprising a plurality of different repetition rates, wherein the optical pump pulses having different repetition rates generate optical supercontinuum pulses having different repetition rates;

wherein the optical pulse energy is fixed as the pulse to pulse separation is increased with reducing repetition rate.