Single-transverse-mode linear polarization state large-divergence-angle laser light source for interference measurement

Abstract

The invention discloses a single-transverse-mode linear polarization state large-divergence-angle laser light source for interference measurement. The single-transverse-mode linear polarization statelarge-divergence-angle laser light source comprises a laser, an optical fiber coupler, a standard single-mode optical fiber, a polarization controller and a large-numerical-aperture optical fiber; laser emitted by the laser is coupled into the standard single-mode optical fiber through the optical fiber coupler; the single-mode optical fiber passes through the polarization controller and then is connected with the large-numerical-aperture optical fiber through a mode field matching welding point; and finally the conducted laser is output through an optical fiber tapering output end. The laseris transitionally coupled to the large-numerical-aperture optical fiber by using the standard single-mode optical fiber; the laser transmission efficiency is improved through the mode field matching welding point; the single-mode optical fiber is coiled based on the stress birefringence principle, and the polarization state of the transmission laser of dissimilar welding optical fibers can be controlled; the output end of the large-numerical-aperture optical fiber is tapered, so that the light-emitting area of the output end can be reduced, and a laser divergence angle can be improved; finally, a large-divergence-angle laser light source with a single transverse mode and a linear polarization state is obtained, so that the background uniformity of interference fringes in the interference measurement is improved.

Description

technical field

[0001] The invention belongs to the field of laser light sources, in particular to a single transverse mode linear polarization state large divergence angle laser light source for interferometric measurement. Background technique

[0002] Laser has excellent time coherence and is widely used in the field of interferometry. For example, a laser interferometer uses a laser as a light source to obtain interference fringes with high contrast and improve measurement accuracy. Currently, HeNe lasers are widely used as light sources in commercial interferometers. Moreover, the fiber-coupled laser technology can separate the light source from the host of the interferometer, reducing the volume and heat source of the interferometer.

[0003] A standard single-mode fiber is usually used as the coupling fiber of the He-Ne laser, which can filter out high-frequency noise and improve the signal-to-noise ratio of the output wavefront. However, the use of standard single...

Examples

Embodiment 1

[0054] combine figure 1 , the single transverse mode linear polarization state large divergence angle laser light source used for interferometry according to the present invention, the laser (1) uses a HeNe laser emitting 633nm visible red light; the standard single-mode fiber 3 uses Nufern 630- HP, with a core diameter of 4um, a cladding diameter of 125um, and a numerical aperture NA of 0.13; the polarization controller 4 used is a manual polarization controller model FPC030 from Thorlabs, which has three 27mm coil slots; the large numerical aperture fiber 6 is NufernUHNA1 , the mode field diameter is 2.5um, the cladding diameter is 125um, and the numerical aperture NA is 0.28.

[0055] The HeNe laser 1 is coupled into the standard single-mode fiber 3 through the fiber coupler 2, and the lateral and axial defocus of the coupler lens is adjusted to increase the coupling power as much as possible.

[0056] combine figure 2 , the standard single-mode optical fiber 3 is coiled...

technical field

[0001] The invention belongs to the field of laser light sources, in particular to a single transverse mode linear polarization state large divergence angle laser light source for interferometric measurement. Background technique

[0002] Laser has excellent time coherence and is widely used in the field of interferometry. For example, a laser interferometer uses a laser as a light source to obtain interference fringes with high contrast and improve measurement accuracy. Currently, HeNe lasers are widely used as light sources in commercial interferometers. Moreover, the fiber-coupled laser technology can separate the light source from the host of the interferometer, reducing the volume and heat source of the interferometer.

[0003] A standard single-mode fiber is usually used as the coupling fiber of the He-Ne laser, which can filter out high-frequency noise and improve the signal-to-noise ratio of the output wavefront. However, the use of standard single...

Examples

Embodiment 1

[0054] combine figure 1 , the single transverse mode linear polarization state large divergence angle laser light source used for interferometry according to the present invention, the laser (1) uses a HeNe laser emitting 633nm visible red light; the standard single-mode fiber 3 uses Nufern 630- HP, with a core diameter of 4um, a cladding diameter of 125um, and a numerical aperture NA of 0.13; the polarization controller 4 used is a manual polarization controller model FPC030 from Thorlabs, which has three 27mm coil slots; the large numerical aperture fiber 6 is NufernUHNA1 , the mode field diameter is 2.5um, the cladding diameter is 125um, and the numerical aperture NA is 0.28.

[0055] The HeNe laser 1 is coupled into the standard single-mode fiber 3 through the fiber coupler 2, and the lateral and axial defocus of the coupler lens is adjusted to increase the coupling power as much as possible.

[0056] combine figure 2 , the standard single-mode optical fiber 3 is coiled...

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