CN105024264A - Vector light field output laser - Google Patents

Abstract

The invention relates to a vector light field output laser, which includes a conical light field return element, a reflector with mechanical adjustment, and a pump source. The conical light field return element is an axisymmetric prism structure. It is the top plane perpendicular to the axis of symmetry, and between the conical surface and the top plane is a circular conical surface. The conical surface light field return element’s section plane along the direction of the symmetry axis is an axisymmetric pentagon, and the top conical surface The top is facing the reflector, and the symmetry axis of the conical light field return element is perpendicular to the laser reflection film on the reflector. The reflector and the conical light field return element form a laser resonator, and the angle between the top conical surface and the symmetry axis is the laser working wavelength Brewster's angle, the output beam of the pump source is irradiated on the return element of the conical light field. The invention has the advantages of simple structure, convenient construction, high reliability, strong flexibility, wide application range, can realize longitudinal polarization light field output, and high beam quality.

Description

A Vector Light Field Output Laser

technical field

The invention relates to an optical technology, in particular to a vector light field output laser.

Background technique

A laser is a device that uses the principle of stimulated radiation to amplify or oscillate light in certain excited substances. At present, common laser generating devices include gas lasers, solid-state lasers, dye lasers, and semiconductor lasers. The working substance of the solid-state laser is composed of optically transparent crystal or glass as the matrix material of the solid-state laser, doped with active ions or other active substances. Such working substances should generally have good physical-chemical properties, narrow fluorescent spectral lines, strong and broad absorption bands and high fluorescent quantum efficiency. Solid-state lasers are widely used in laser processing, photoelectric detection, optical microscopy, optical micromanipulation, optical information storage, spectral technology, laser measurement, optical fiber communication, laser guidance, laser medicine, optical communication and other fields.

In the prior art, there is a solid-state laser, see the authorized US patent, US patent name: Solid-state laser, patent number: US8165182B2, authorized time: April 24, 2012, inventor: Adolf Giesen et al. The optically pumped solid-state laser has considerable advantages, but there are still some essential deficiencies: 1) The system uses a solid-state gain structure based on reflective components, and also includes a mirror-based compensation module, which makes the system highly demanding on the preparation process. The process of preparing the laser is complex and difficult; 2) The laser system is set in the two mirrors in the reflective compensation module, and the mutual position and orientation of all devices are required to be set, which leads to complex structure of the entire system, difficulty in installation and adjustment, and reduced reliability , which limits the use range and application flexibility of the light source; 3) This laser is essentially unable to achieve longitudinal polarization state light field output.

Contents of the invention

The present invention aims at the problems existing in the existing optically pumped solid-state lasers, and proposes a vector light field output laser, which is simple in structure, easy to construct, high in reliability, strong in flexibility, wide in application range, and can realize longitudinal polarization state light field Output, beam quality is high.

The technical solution of the present invention is: a vector light field output laser, including a conical light field return element, a reflector, a mechanical adjustment component, and a pump source. The conical light field return element is an axisymmetric prism structure, and the front end is a top cone Curved surface, the rear end is a top plane perpendicular to the axis of symmetry, and a circular conical surface is formed between the conical surface and the top plane, and the tangent plane of the conical surface light field return element along the direction of the symmetry axis is an axisymmetric pentagon , the top of the conical light field return element is facing the reflector, the symmetry axis of the conical light field return element is perpendicular to the laser reflection film on the reflector, the reflector and the conical light field return element constitute a laser resonant cavity, and the top cone The angle between the curved surface and the axis of symmetry is the Brewster angle of the working wavelength of the laser, the output beam of the pump source is irradiated on the return element of the conical light field, and the mirror is connected with the mechanical adjustment part.

The material of the conical surface light field return element is one of Nd-doped YAG, LiF2, self-activated laser crystal and tunable laser crystal.

The reflectivity of the laser reflective film on the reflector at the laser working wavelength is greater than 98%.

The pumping source is one of incoherent light sources, semiconductor lasers, gas lasers, solid-state lasers, and laser diodes.

The beneficial effect of the present invention is that: the vector light field output laser of the present invention is based on the working principle of a solid laser, combined with the optical effect of the conical surface and the polarization selection characteristics of the Brewster angle, and the laser resonator is composed of a reflector and a conical light field return element; The conical light field return element is an axisymmetric prism structure of a solid-state laser gain medium. The device of the present invention has a simple manufacturing process, a simple structure, and is easy to construct; The symmetry axis of the field return element is perpendicular to the laser reflection film of the reflector, and the angle between the top conical surface and the symmetry axis is the Brewster angle of the laser working wavelength, so as to realize the generation of radially polarized vector beams in the laser resonator cavity, and the light field parallel to the optical axis in the circle Reflection occurs on the circular conical surface, and the conical surface light field return element is not only a resonant cavity reflector but also a laser working medium, which has the characteristics of high reliability, strong flexibility, and wide application range; under optical pumping, the conical surface light The field return element generates stimulated radiation, and the top plane of the conical light field return element can realize longitudinally polarized light field output.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the vector light field output laser of the present invention.

Detailed ways

As shown in Figure 1, the schematic diagram of the vector light field output laser, the vector light field output laser includes a conical light field return element 1, a mirror 2, a mechanical adjustment component 3, and a pump source 4; the conical light field return element 1 is a solid state The axisymmetric prism structure of the laser gain medium, the front end is a top conical surface 101, the rear end is a top plane 103 perpendicular to the axis of symmetry, and between the conical surface 101 and the top plane 103 is a circular conical surface 102, along the axis of symmetry The tangential plane of the outer edge of the direction along its axis of symmetry is an axisymmetric pentagon; the top of the conical surface 101 of the conical surface light field return element 1 faces the reflector 2, and the symmetry axis of the conical surface light field return element 1 (dotted in the figure line) perpendicular to the laser reflection film on the mirror 2, the laser resonant cavity is composed of the mirror 2 and the conical light field return element 1, and the angle between the top conical surface 101 and the symmetry axis is the Brewster angle θ of the laser working wavelength; The light beam emitted by the pump source 4 is irradiated on the conical light field return element 1 , and the mirror 2 is connected with the mechanical adjustment component 3 .

In this embodiment, the material of the conical light field return element 1 is neodymium-doped yttrium aluminum garnet, the reflection surface of the mirror has a reflectivity of 99% at the laser working wavelength, and the pump source 4 is a laser diode with a wavelength of 808nm. One, the mechanical adjustment part 3 adopts a five-dimensional adjustment frame, and the laser working wavelength of the system is 1064nm.

The working process of this embodiment is: the 808 nm wavelength pump light field emitted by the pump source 4 is refracted onto the conical surface light field return element 1, and the conical surface light field return element 1 generates stimulated radiation; the laser resonator is formed by the reflector 2 and a conical surface light field return element 1; the conical surface light field return element 1 is an axisymmetric prism structure of a solid-state laser gain medium, the top conical surface 101 of the conical surface light field return element 1 faces the reflector 2, and the conical light field The symmetry axis of the return element 1 is perpendicular to the laser reflection film of the reflector 2, and the angle between the top conical surface 101 and the symmetry axis is the Brewster angle of the laser working wavelength. Under optical pumping, the radially polarized vector beam in the laser resonator is generated , the light field parallel to the optical axis is reflected on the circular conical surface 103, the top plane 103 of the conical light field return element realizes the output of the longitudinal polarization state light field 5, and the mirror 2 is connected with the mechanical adjustment part 3 to realize the laser mode selection output. The reflector 2 and the movable module are fixed to each other so as to be adjusted. In the actual adjustment process, the parameters that can be adjusted include translation adjustments such as front and rear, left and right, etc. For example, when a spherical reflector is selected, the mechanical adjustment parts can be adjusted with angles. In our actual experiments, position translation and angle fine-tuning can realize laser mode control, and the mode changes greatly, and can realize the transformation from fundamental mode to high-order mode, and obtain rectangular coordinate system, cylindrical coordinate system and ellipse coordinate system The laser light field in this card mode.

In this embodiment, the light field output in the longitudinal polarization state with a wavelength of 1064 nanometers is realized on the side of the top plane 103 of the conical light field return element 1 . The invention has the characteristics of simple structure, convenient construction, high reliability, strong flexibility, wide application range, can realize longitudinal polarization state light field output, high beam quality and the like.

The material of the conical surface light field return element 1 is one of Nd-doped YAG, yttrium lithium fluoride, self-activated laser crystal, and tunable laser crystal.

The laser reflective film on the reflector 2 has a reflectivity greater than 98% at the laser working wavelength.

The pumping source 4 is one of incoherent light sources, semiconductor lasers, gas lasers, solid-state lasers, and laser diodes.

The working principle and technology of the solid-state laser, the principle of Brewster's angle action, the processing technology of the conical optical working surface, optical pumping, and the focusing properties of the vector light field in the present invention are all mature technologies. The invention point of the present invention is based on the principle of solid-state laser and conical surface optics, combined with the polarization selection characteristics of Brewster's angle, to construct a conical light field return element as an active resonant cavity mirror, and to realize polarization state selection by using Brewster's angle. The intracavity radially polarized vector beam is generated, based on the circular conical surface, the intracavity radially polarized vector beam is strongly focused, and the output of the longitudinally polarized light field is realized.

Claims (4)

1. A vector light field output laser is characterized in that it comprises a conical surface light field return element, a reflector, a mechanical adjustment component, a pump source, and the conical surface light field return element is an axisymmetric prism structure, and the front end is a top conical surface , the rear end is the top plane perpendicular to the axis of symmetry, and between the conical surface and the top plane is a circular conical surface, and the tangent plane of the conical surface light field return element along the direction of the symmetry axis is an axisymmetric pentagon, The top of the conical light field return element is facing the reflector, and the symmetry axis of the conical light field return element is perpendicular to the laser reflection film on the reflector. The reflector and the conical light field return element form a laser resonant cavity, and the top conical surface The included angle with the symmetry axis is the Brewster angle of the working wavelength of the laser, the output beam of the pump source is irradiated on the conical light field return element, and the reflector is connected with the mechanical adjustment part. 2. The vector light field output laser according to claim 1, wherein the material of the conical light field return element is Nd-doped yttrium aluminum garnet, yttrium lithium fluoride, self-activated laser crystal, tunable laser crystal One of. 3 . The vector light field output laser according to claim 1 , wherein the reflectivity of the laser reflective film on the reflector at the laser working wavelength is greater than 98%. 4. The vector light field output laser according to claim 1, wherein the pumping source is one of an incoherent light source, a semiconductor laser, a gas laser, a solid-state laser, and a laser diode.