Laser light source

Patent metadata

Field	Value
Publication number	US-9395550-B2
Application number	US-201314418344-A
Country	US
Kind code	B2
Filing date	Aug 28, 2013
Priority date	Aug 30, 2012
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

The present invention relates to a laser light source which reduces wavelength-dependent difference of focal position of condensed light when multicolor light with a wide spectral width is collimated and then condensed. The laser light source incorporates a collimator device, in which an installation position of a collimating lens with respect to a laser light entrance portion is set so that a beam waist position of laser light having passed through the collimating lens shifts closer to the collimating lens with a shorter-wavelength-side wavelength component out of wavelength components included in the laser light.

First claim

The invention claimed is:

1. A laser light source comprising:
a single-mode optical fiber which emits laser light with a spectral width of several hundred nm from a core portion thereof;
a collimating lens which collimates the laser light divergently emitted from the single-mode optical fiber;
a condensing lens which condenses the laser light collimated by the collimating lens;
a laser light entrance portion which sets an entrance position of the laser light emitted from the single-mode optical fiber; and
a collimating lens installation portion which fixes the collimating lens,
wherein an installation position of the collimating lens with respect to the laser light entrance portion is set so that a beam waist position of the laser light having passed through the collimating lens shifts closer to the collimating lens with a shorter-wavelength-side wavelength component out of wavelength components included in the laser light.

2. The laser light source according to claim 1 , wherein the laser light includes a wavelength component the beam waist position of which is located on the single-mode optical fiber side with respect to the collimating lens.

3. The laser light source according to claim 1 , wherein the collimating lens has a light entrance face for the laser light emitted from the single-mode optical fiber to enter and a light exit face for the laser light to exit, and
wherein when, with respect to a position of the light exit face of the collimating lens arranged so that a focal point of the collimating lens is located on the light exit end face of the single-mode optical fiber at a center wavelength of the laser light, a negative region is defined on the single-mode optical fiber side and a positive region on the condensing lens side,
the collimating lens is installed in the range of +100 μm to +1000 μm along the optical axis of the laser light emitted from the single-mode optical fiber.

4. The laser light source according to claim 1 , comprising: a condensing lens installation portion which fixes the condensing lens, wherein an installation position of the condensing lens with respect to the collimating lens is set so as to fall within a region where chromatic aberration of the laser light condensed through the condensing lens becomes minimum.

5. The laser light source according to claim 1 , wherein the collimating lens is a lens that reduces chromatic aberration.

6. The laser light source according to claim 1 , wherein the condensing lens is a lens that reduces chromatic aberration.

7. The laser light source according to claim 1 , comprising: a position adjustment portion provided for either one of the laser light entrance portion and the collimating lens installation portion, the position adjustment portion enabling position adjustment of a distance between the entrance position of the laser light and a center position of the collimating lens in a 10-μm or smaller level.

Assignees

• Sumitomo Electric Industries

Inventors

• Nagano Shigehiro

Classifications

• H01S3/067

  Fibre lasers · CPC title

• H01S3/005 Primary

  Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping (shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B) · CPC title

• G02B19/0047

  for use with a light source (G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005) · CPC title

• B23K26/0665

  by beam condensation on the workpiece, e.g. for focusing · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title