Broadband or mid-infrared fiber light sources

• US 9,726,539 B2
• Filed: 08/26/2016
• Issued: 08/08/2017
• Est. Priority Date: 11/18/2005
• Status: Expired due to Fees

• Current Assignee: Omni Medsci, Inc.
• Original Assignee: Omni Medsci, Inc.
• Inventors: Islam, Mohammed N.
• Primary Examiner(s): PAK, SUNG H
• Application Number:
  US15/248,230
• Publication Number:
  US 20160363482A1
• Time in Patent Office: 347 Days
• Field of Search: None
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G01J 2003/102 Plural sources
• CPC Class Codes: G01J 2003/423 Spectral arrangements using lasers, e.g. tunable
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0245 using an optical amplifier of light, e.g. doped fiber
• CPC Class Codes: G01J 3/108 for measurement in the infrared range
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G02B 6/29349 Michelson or Michelson/Gires-Tournois configuration, i.e. based on splitting and interferometrically combining relatively delayed signals at a single beamsplitter
• CPC Class Codes: G02F 1/3528 for producing a supercontinuum
• CPC Class Codes: G02F 1/365 in an optical waveguide structure G02F1/377, G02F1/395 take precedence
• CPC Class Codes: G02F 2202/32 Photonic crystals
• CPC Class Codes: H01S 2301/085 solitons
• CPC Class Codes: H01S 3/06725 Fibre characterized by a specific dispersion, e.g. for pulse shaping in soliton lasers or for dispersion compensating [DCF]
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/094007 Cladding pumping, i.e. pump light propagating in a clad surrounding the active core
• CPC Class Codes: H01S 3/094069 Multi-mode pumping
• CPC Class Codes: H01S 3/094076 Pulsed or modulated pumping H01S3/1024 takes precedence
• CPC Class Codes: H01S 3/1024 for pulse generation
• CPC Class Codes: H01S 3/302 in an optical fibre
• CPC Class Codes: H01S 5/0064 Anti-reflection components, e.g. optical isolators
• CPC Class Codes: H01S 5/0085 : for modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 5/0092 : for nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity
• CPC Class Codes: H01S 5/1092 : Multi-wavelength lasing
• CPC Class Codes: H01S 5/146 : using a fiber as external cavity
• CPC Class Codes: H01S 5/4012 : Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms

Abstract

A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

Claims

1. A white light spectroscopy system, comprising:

a super continuum light source comprising;

an input light source, including one or more semiconductor diodes, to generate an input beam that comprises a wavelength shorter than 2.5 microns;

one or more optical amplifiers to receive at least a portion of the input beam and form an amplified optical beam having a spectral width, wherein at least a portion of the one or more optical amplifiers comprises a cladding-pumped fiber amplifier; and

a nonlinear element comprising a photonic crystal fiber to receive at least a portion of the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam,

wherein at least a portion of the output beam is in the visible wavelength range from 0.4 microns to 0.6 microns,

wherein the output beam is pulsed with a repetition rate of 1 Megahertz or higher, and

the white light spectroscopy system further comprising;

at least one of a lens and a mirror to receive at least a portion of the output beam, to send the at least a portion of the output beam to a scanning stage, and to deliver at least part of the received output beam to a sample; and

a detection system comprising dispersive optics and one or more narrow band filters comprising slits followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

2. The white light spectroscopy system of claim 1 wherein the output beam pulse width is greater than 100 psec.

3. The white light spectroscopy system of claim 2 further comprising a filter coupled to the at least one of a lens and a mirror.

4. The white light spectroscopy system of claim 3 wherein an average output power of the output beam is 20 mW or more and wherein an average intensity of the at least a portion of the output beam is less than approximately 50 MW/cm².

5. The white light spectroscopy system of claim 4 wherein the input light source comprises two or more semiconductor diodes, and wherein the super continuum light source includes a beam combiner to combine at least a portion of the light from the two or more semiconductor diodes and to generate a multiplexed input beam coupled to the one or more optical amplifiers.

6. A white light spectroscopy system, comprising:

a super continuum light source comprising;

an input light source, including one or more semiconductor diodes, to generate an input beam that comprises a wavelength shorter than 2.5 microns;

one or more optical amplifiers to receive at least a portion of the input beam and form an amplified optical beam having a spectral width, wherein at least a portion of the one or more optical amplifiers comprises a cladding-pumped fiber amplifier; and

a nonlinear element to receive at least a portion of the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam,

wherein at least a portion of the output beam is in the visible wavelength range from 0.4 microns to 0.6 microns,

wherein the output beam is pulsed with a repetition rate of 1 Megahertz or higher, and

the white light spectroscopy system further comprising;

at least one of a lens and a mirror to receive at least a portion of the output beam, to send the at least a portion of the output beam to a scanning stage, and to deliver at least a portion of the received output beam to a sample; and

a detection system comprising one or more narrow band filters comprising slits followed by one or more detectors.

7. The white light spectroscopy system of claim 6 wherein the nonlinear element comprises a photonic crystal fiber.

8. The white light spectroscopy system of claim 7 wherein the detection system permits approximately simultaneous measurement of at least two wavelengths from the sample.

9. The white light spectroscopy system of claim 8 wherein the output beam pulse width is greater than 100 psec.

10. The white light spectroscopy system of claim 9 wherein the detection system further comprises dispersive optics to spread a reflected beam from the sample before reaching the one or more detectors.

11. The white light spectroscopy system of claim 10 wherein the white light spectroscopy system further comprises a filter coupled to the at least one of a lens and a mirror.

12. The white light spectroscopy system of claim 11 wherein an average output power of the output beam is 20 mW or more and wherein an average intensity of the at least a portion of the output beam is less than approximately 50 MW/cm².

13. The white light spectroscopy system of claim 12 wherein the input light source comprises two or more semiconductor diodes, and wherein the super continuum light source includes a beam combiner to combine at least a portion of the light from the two or more semiconductor diodes and to generate a multiplexed input beam coupled to the one or more optical amplifiers.

14. The white light spectroscopy system of claim 6 wherein the detection system permits approximately simultaneous measurement of at least two wavelengths from the sample.

15. The white light spectroscopy system of claim 6 wherein the output beam pulse width is greater than 100 psec.

16. The white light spectroscopy system of claim 6 wherein the detection system further comprises dispersive optics to spread a reflected beam from the sample before reaching the one or more detectors.

17. The white light spectroscopy system of claim 6 wherein the repetition rate is selectable.

18. The white light spectroscopy system of claim 6 wherein an average output power of the output beam is 20 mW or more and wherein an average intensity of the at least a portion of the output beam is less than approximately 50 MW/cm².

19. The white light spectroscopy system of claim 6 wherein the input light source comprises two or more semiconductor diodes, and wherein the super continuum light source includes a beam combiner to combine at least a portion of the light from the two or more semiconductor diodes and to generate a multiplexed input beam coupled to the one or more optical amplifiers.

20. A white light spectroscopy system, comprising:

a super continuum light source comprising;

an input light source, including one or more semiconductor diodes, to generate an input beam that comprises a wavelength shorter than 2.5 microns;

one or more optical amplifiers to receive at least a portion of the input beam and form an amplified optical beam having a spectral width, wherein at least a portion of the one or more optical amplifiers comprises a cladding-pumped fiber amplifier; and

a nonlinear element comprising a photonic crystal fiber to receive at least a portion of the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam,

wherein at least a portion of the output beam is in the visible wavelength range from 0.4 microns to 0.6 microns,

wherein the output beam is pulsed with a repetition rate of 1 Megahertz or higher, and

the white light spectroscopy system further comprising;

a filter and at least one of a lens and a mirror to receive at least a portion of the output beam, to send the at least a portion of the output beam to a scanning stage, and to deliver at least part of the received output beam to a sample; and

a detection system comprising one or more narrow band filters comprising slits followed by one or more detectors.