Fiber bundle and laser apparatus using the fiber bundle of manufacturing the same

• US 6,272,155 B1
• Filed: 06/30/1998
• Issued: 08/07/2001
• Est. Priority Date: 06/30/1997
• Status: Expired due to Fees

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hoya Corporation
• Inventors: Sekiguchi, Hiroshi
• Primary Examiner(s): SCHUBERG, DARREN E
• Application Number:
  US09/107,130
• Time in Patent Office: 1,134 Days
• Field of Search: 372/6, 372/71, 372/75, 385/89, 385/115, 385/120
• US Class Current: 372/6
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/06 the relative position of the fibres being the same at both ends, e.g. for transporting images
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: H01S 3/067 Fibre lasers
• CPC Class Codes: H01S 3/07 consisting of a plurality of parts, e.g. segments H01S3/067 takes precedence
• CPC Class Codes: H01S 3/094053 Fibre coupled pump, e.g. delivering pump light using a fibre or a fibre bundle
• CPC Class Codes: H01S 3/2383 Parallel arrangements

Abstract

In a fiber bundle (100) in which one ends of a plurality of optical fibers including cores (111a-111p), respectively, are bundled as a bundled position, the fiber bundle includes in the bundled portion a clad (112a-112p) having a refractive index less than that of each of the cores and surrounding the cores so that the cores are positioned near to each other with a minimum distance left between two adjacent ones of the cores. The minimum distance is decided so that transverse modes of laser beams propagated through the above-mentioned two adjacent ones of the cores do not affect each other. Typically, in the fiber bundle, different ends of the optical fibers are kept separated as a separated portion without being bundled. In this case, each of the cores may include a laser active material which produces, when excited by an excitation beam incident to the different end of each of the optical fibers, the laser beam propagated through each of the cores from the different end of each of the optical fibers to the one end of each of the optical fibers.

Claims

1. A laser apparatus for producing an output laser beam, wherein:

said laser apparatus comprising;

a fiber bundle in which in which one ends of a plurality of optical fibers are bundled as a bundled portion, said optical fibers including cores, respectively, each of said cores including a laser active material which produces a laser beam propagated through each of said cores towards said one end of said optical fibers, said fiber bundle outputting the laser beams from said one ends of the optical fibers collectively as said output laser beam; and

exciting means for exciting said laser active material of each of said cores to make said laser active material of each of said cores produce said laser beam;

said fiber bundle comprising in said bundled portion;

a clad having a refractive index less than that of each of said cores and surrounding said cores so that said cores are positioned near to each other with a minimum distance left between two adjacent ones of said cores, said minimum distance being decided so that transverse modes of the laser beams propagated through said two adjacent ones of the cores do not affect each other;

different ends of said fibers being kept separated as a separated portion without being bundled in said fiber bundle;

said fiber bundle comprising in said separated portion;

first clads, each of which has a first refractive index less than that of each of said cores and surrounds each of said cores; and

second clads, each of which has a second refractive index less than that of each of said first clads and surrounds each of said first clads.

2. A laser apparatus as claimed in claim 1, wherein said exciting means excites the laser active material of each of said cores by introducing an excitation beam into the first clad of said different end of each of said optical fibers.

3. A laser apparatus as claimed in claim 1, wherein said laser apparatus further comprises:

condensing means for condensing said output laser beam as a condensed laser beam.