Broadband or mid-infrared fiber light sources

• US 9,077,146 B2
• Filed: 02/21/2014
• Issued: 07/07/2015
• 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:
  US14/186,171
• Publication Number:
  US 20150008344A1
• Time in Patent Office: 501 Days
• Field of Search: None
• US Class Current: 1/1
• 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

An optical system for use in material processing includes a plurality of semiconductor diodes coupled to a beam combiner to generate a multiplexed optical beam. A cladding pumped fiber amplifier or laser receives the multiplexed optical beam and forms an intermediate beam having at least a first wavelength. An optical element receives the intermediate beam and forms an output beam with an output beam wavelength, wherein the output beam wavelength is at least in part longer than the first wavelength. A subsystem includes lenses or mirrors to deliver a delivered portion of the output beam to a sample. The delivered output beam has a temporal duration greater than about 30 picoseconds, a repetition rate between continuous wave and Megahertz or higher, and a time averaged intensity of less than approximately 50 MW/cm². The output beam has a time averaged output power of 20 mW or more.

Claims

1. An optical system for use in material processing, the system comprising:

a plurality of semiconductor diodes, each of the diodes configured to generate an optical beam;

a beam combiner configured to receive at least a portion of the optical beams from the plurality of semiconductor diodes and to generate a multiplexed optical beam; and

a cladding-pumped fiber amplifier or laser configured to receive at least a portion of the multiplexed optical beam and to form an intermediate beam having at least a first wavelength;

an optical element configured to receive at least a portion of the intermediate beam and to form an output beam with an output beam wavelength, wherein at least a portion of the output beam wavelength is longer than at least a portion of the first wavelength; and

a subsystem comprising one or more lenses or mirrors configured to receive a received portion of the output beam and to deliver a delivered portion of the output beam to a sample, wherein the delivered portion of the output beam has a temporal duration greater than approximately 30 picoseconds, wherein the delivered portion of the output beam has a repetition rate between continuous wave and Megahertz or higher, wherein a time averaged output power of the output beam is about 20 mW or more, and wherein a time averaged intensity of the delivered portion of the output beam is less than approximately 50 MW/cm².

2. The optical system of claim 1, wherein at least a portion of the delivered portion of the output beam is scanned across at least a part of the sample.

3. The optical system of claim 1, wherein at least a portion of the optical element comprises a crystal material or a Raman wavelength shifter.

4. The optical system of claim 1, wherein at least a portion of the sample comprises one or more powdered substances.

5. The optical system of claim 1, wherein at least a portion of the sample comprises a multi-layered structure.

6. The optical system of claim 1, wherein at least a portion of the sample is selected from the group consisting of hydro-carbons, amide groups, plasticizer and benzene rings.

7. An optical system for use in material processing, the system comprising:

one or more semiconductor diodes configured to generate an input beam, wherein at least a portion of the input beam comprises a wavelength shorter than about 2.5 microns;

one or more optical amplifiers configured to receive at least the portion of the input beam and to communicate an intermediate beam to an output end of the one or more optical amplifiers; and

one or more optical fibers configured to receive at least a portion of the intermediate beam and to propagate the at least a portion of the intermediate beam to form at a distal end of the one of more optical fibers a first optical beam having at least a first wavelength;

a nonlinear element configured to receive at least a portion of the first optical beam and to wavelength shift at least a portion of the first wavelength through a nonlinear effect in the nonlinear element to form an output beam with an output beam wavelength, wherein at least a portion of the output beam wavelength is longer than the at least a portion of the first wavelength; and

a subsystem comprising one or more lenses or mirrors configured to receive a received portion of the output beam and to deliver a delivered portion of the output beam to a sample, wherein the delivered portion of the output beam has a temporal duration greater than approximately 30 picoseconds, wherein the delivered portion of the output beam has a repetition rate between continuous wave and Megahertz or higher, wherein a time averaged output power of the output beam is about 20 mW or more, and wherein a time averaged intensity of the delivered portion of the output beam is less than approximately 50 MW/cm².

8. The system of claim 7, wherein at least a portion the one or more optical amplifiers form a cladding-pumped fiber amplifier or laser, and wherein at least a portion of the nonlinear element comprises a crystal material or a Raman wavelength shifter.

9. The system of claim 7, wherein at least a portion of the delivered portion of the output beam is scanned across at least a part of the sample.

10. The system of claim 7, wherein at least a portion of the sample comprises one or more powdered substances.

11. The system of claim 7, wherein at least a portion of the sample is selected from the group consisting of hydro-carbons, amide groups, plasticizer and benzene rings.

12. The system of claim 7, wherein at least a portion of the sample comprises a multi-layered structure.

13. An optical system for use in material processing, the system comprising:

a plurality of semiconductor diodes, each of the diodes configured to generate an optical beam;

a beam combiner configured to receive at least a portion of the optical beams from the plurality of semiconductor diodes and to generate a multiplexed optical beam; and

an optical fiber configured to receive at least a portion of the multiplexed optical beam and to communicate the at least a portion of the multiplexed optical beam to form an intermediate beam;

a light guide configured to receive at least a portion of the intermediate beam and to propagate the at least a portion of the intermediate beam to form an output beam having at least one wavelength; and

a subsystem comprising one or more lenses or mirrors configured to receive a received portion of the output beam and to deliver a delivered portion of the output beam to a sample comprising one or more powdered substances, wherein the delivered portion of the output beam has a temporal duration greater than approximately 30 picoseconds, wherein the delivered portion of the output beam has a repetition rate between continuous wave and Megahertz or higher, wherein a time averaged output power of the output beam is about 20 mW or more, and wherein a time averaged intensity of the delivered portion of the output beam is less than approximately 50 MW/cm².

14. The optical system of claim 13, wherein at least a portion of the output beam wavelength is in a wavelength range between approximately 1700 nm and 1750 nm.

15. The optical system of claim 13, wherein at least a portion of the optical fiber comprises a gain fiber doped with erbium, ytterbium or thulium.

16. The optical system of claim 13, wherein at least a portion of the light guide comprises a Raman wavelength shifter.

17. The optical system of claim 13, wherein at least a portion of the sample comprises one or more multi-layered structures.

18. The optical system of claim 13, wherein at least a portion of the delivered portion of the output beam is scanned across at least a part of the sample.

19. The optical system of claim 13, wherein at least a portion of the sample is selected from the group consisting of hydro-carbons, plasticizers and benzene rings.

20. The optical system of claim 13, wherein at least a portion of the sample comprises one or more amide groups.