CN105938973A - Novel high-precision laser energy/power attenuator - Google Patents

Abstract

A new type of high-precision laser energy/power attenuator, which consists of a laser, a first polarization beam splitter, a prism fixture, and a second polarization beam splitter; the first polarization beam splitter and the second polarization beam splitter are sequentially arranged on the laser One side, and the axes of the first polarizing beam splitting prism and the second polarizing beam splitting prism are on the same straight line as the laser light emitted by the laser, and the prism clamps are respectively located on the first polarizing beam splitting prism and the second polarizing beam splitting prism to play a fixed clamping The effect; the first polarizing beam splitting prism and the second polarizing beam splitting prism can freely rotate with the laser beam propagating direction as the axis. The invention provides a substantial improvement to the problems of insufficient extinction ratio, complex adjustment process, difficult handling of stray light and the like existing in the traditional laser energy/power attenuator.

Description

A New High Precision Laser Energy/Power Attenuator

technical field

The invention relates to a novel high-precision continuously adjustable laser output energy/power attenuator, which belongs to the field of lasers.

Background technique

With the rapid development of laser technology, laser plays an increasingly irreplaceable role in industry, medicine, military industry, scientific research and other fields. For many fine processing applications such as laser marking, liquid crystal repair, large-scale integrated circuit laser etching and micromachining, etc., the control accuracy of laser output energy is getting higher and higher, and the vast majority of lasers, their matching The adjustment accuracy of the power supply cannot meet the requirements of use, especially when the output energy or power required for the operation of the laser is lower than 50% of the full load energy/power, adjusting the laser power supply current or operating voltage often brings laser energy/power stability The deterioration of the laser energy/power attenuator becomes an essential accessory.

The structure of the traditional laser energy/power attenuator is to put a half-wave plate corresponding to the laser wavelength between two parallel Brewster film polarizers, and change the optical axis of the wave plate and the laser polarization by rotating The included angle Ф is used to control the transmitted laser energy/power. Its design has many limitations: First, the extinction effect of this system depends entirely on the half-wave plate with a low extinction ratio, resulting in the attenuator being set to a no-light state under high-energy/power laser output, but the actual state is still There is laser output, that is, light leakage phenomenon; second, the placement position of the polarizer of the traditional attenuator has been preset, and the polarization direction of the laser output is required. The polarization direction is adjusted by the method of the film polarizer, but it also increases the complexity and the cost of use; thirdly, in the process of rotating the half-wave plate of the traditional attenuator, due to the problem of the reflection angle of the film polarizer, in order to ensure the stray light It will not stir up dust on the inner wall of the attenuator, and it is necessary to add a stray light absorbing device at a position away from the optical path in the direction of the stray light emission, which increases the volume of the attenuator.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention adopts a simple structure based on a polarization splitter prism, and provides substantial improvements to the traditional laser energy/power attenuator's problems of insufficient extinction ratio, complex adjustment process, and difficult handling of stray light.

A novel high-precision laser energy/power attenuator, as shown in Figure 1, its composition includes a laser, a first polarization beam splitter, a prism fixture, a second polarization beam splitter; the first polarization beam splitter and the second polarization beam splitter The prisms are arranged on one side of the laser in sequence, and the axes of the first polarizing beam splitting prism and the second polarizing beam splitting prism are on the same line as the laser light emitted by the laser. The top plays the role of fixed clamping; the first polarizing beam splitter and the second polarizing beam splitting prism can freely rotate with the laser beam propagating direction as the axis.

The working method of the novel high-precision laser energy/power attenuator is as follows: turn on the laser output laser, place the energy meter or power meter in the laser output direction, and rotate the first polarization beam splitter and the second polarization beam splitter synchronously , until the output energy or power detected by the energy meter or power meter is approximately equal to the energy or power of the laser without an attenuator and is recorded as Emax, fix the first polarization beam splitter, and mark the position of the second polarization beam splitter S1; then pass Rotate the second polarization beam splitter to make the laser output energy or power 0, mark the second polarization beam splitter position S2; then rotate the second polarization beam splitter between S1 and S2 to make the output laser energy or power from Emax To extinction (energy or power is 0) and continuously adjustable.

Described a kind of novel high-precision laser energy/power attenuator, as shown in Figure 2, a magneto-optical isolator is set between the first polarization beam splitter and the second polarization beam splitter to form a magneto-optic isolation system; The magneto-optical isolator is coaxial with the laser light emitted by the laser; the polarization rotation angle of the magneto-optic isolator is 45°. The adjustment method of the magneto-optical isolation system is as follows: after adjusting the attenuator as shown in Figure 1, the second polarization beam splitter prism is placed at the position of S1, and the laser output energy or power is Emax, and the magneto-optic isolator Placed between the first polarizing beam splitter and the second polarizing beam splitting prism, making it coaxial with the laser, then adjusting the second polarizing beam splitting prism to make the laser output energy reach Emax again, and fixing the second polarizing beam splitting prism at this time to form a magneto-optic isolate the system.

For the laser light emitted by lasers with different wavelengths, the coating system of the first polarizing beam splitting prism and the second polarizing beam splitting prism can be corresponding to it.

Compared with traditional energy/power attenuators, the beneficial effects of the present invention are:

1) Since the extinction ability of the polarization beam splitter is one to two orders of magnitude higher than that of the wave plate, the dynamic range and adjustable precision of the attenuation energy of the present invention are much larger than the traditional attenuator;

2) The present invention is only composed of two polarizing beam splitters, small in size, simple in structure and low in failure rate;

3) There is no requirement for the initial polarization direction of the laser, and it has strong universality;

4) The emission direction of the stray light generated by the attenuator is perpendicular to the laser output direction, so it can be directly absorbed by the prism fixture without additional stray light absorption device.

Description of drawings

Fig. 1 is the structural representation of the attenuator of the present invention;

Fig. 2 is a schematic structural diagram of the magneto-optical isolation system of the present invention;

Among them: 1 is the laser, 2 is the first polarization beam splitter, 3 is the first prism fixture, 5 is the second prism fixture, 4 is the second polarization beam splitter, 6 is the magneto-optical isolator.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

A new type of high-precision laser energy/power attenuator, as shown in Figure 1, its composition includes a laser 1, a first polarization beamsplitter prism 2, a first prism holder 3, a second prism holder 5, and a second polarization beamsplitter prism 4; The first polarizing beam splitting prism 2 and the second polarizing beam splitting prism 4 are sequentially arranged on one side of the laser 1, and the axes of the first polarizing beam splitting prism 2 and the second polarizing beam splitting prism 4 are on the same straight line as the laser light emitted by the laser 1 , the first prism holder 3 is located on the first polarization beamsplitter prism 2, and the second prism holder 5 is located on the second polarization beamsplitter prism 4, and the prism holder plays the role of fixing and clamping the polarization beamsplitter prism; the first polarization beamsplitter The beam-splitting prism 2 and the second polarization beam-splitting prism 4 can freely rotate with the laser beam propagating direction as the axis.

The novel high-precision laser energy/power attenuator has the following working methods: turn on the laser output laser, place the energy meter or power meter in the laser output direction, and rotate the first polarization beam splitter 2 and the second polarization beam splitter synchronously. Prism 4, until the output energy or power detected by the energy meter or power meter is approximately equal to the energy or power of the laser without an attenuator and recorded as Emax, fix the first polarization beam splitter prism 2, and mark the position of the second polarization beam splitter prism 4 S1; then make the laser output energy or power 0 by rotating the second polarization beam splitter prism 4, mark the position S2 of the second polarization beam splitter prism 4; then rotate the second polarization beam splitter prism 4 between S1 and S2 to make the output The energy or power of the laser is continuously adjustable from Emax to extinction energy or power.

Described a kind of novel high-precision laser energy/power attenuator, as shown in Figure 2, a magneto-optical isolator 6 is set between the first polarization beam splitter prism 2 and the second polarization beam splitter prism 4 to form a magneto-optic isolation system The magneto-optical isolator 6 is coaxial with the laser light emitted by the laser 1; the deflection angle of the magneto-optic isolator 6 is 45°. The adjustment method is: after adjusting the attenuator as shown in Figure 1, the second polarization beam splitter 4 is in the position of S1, and the laser output energy or power is Emax, and the magneto-optical isolator 6 is placed in the first position. Between the polarization beamsplitter prism 2 and the second polarization beamsplitter prism 4, make it coaxial with the laser, then adjust the second polarization beamsplitter prism 4 to make the laser output energy reach Emax again, and fix the second polarization beamsplitter prism 4 at this time to form a magneto-optical isolate the system. Compared with the traditional magneto-optical isolation system, because there is no half-wave plate in this system, its isolation capability is 1 to 2 orders of magnitude higher.

For the different laser wavelengths emitted by the laser, the coating systems of the first polarizing beam splitting prism 2 and the second polarizing beam splitting prism 4 correspond to them.

If you need to increase the ease of use and adjustment accuracy of the attenuator, you can connect the fixture to the stepper motor, and the energy/power output with accurate numerical marking can be realized through software programming.

Claims (5)

1. A novel high-precision laser energy/power attenuator, characterized in that it consists of a laser (1), a first polarizing beam splitter (2), a first prism fixture (3), a second polarizing beam splitting prism (4 ), the second prism fixture (5); the first polarizing beam splitting prism (2) and the second polarizing beam splitting prism (4) are sequentially arranged on the side of the laser (1), and the first polarizing beam splitting prism (2) and The axis of the second polarization beamsplitter prism (4) is on the same straight line as the laser light emitted by the laser (1), the first prism fixture (3) is located on the first polarization beamsplitter prism (2), and the second prism fixture (5) Located on the second polarization beam splitter prism (4) to play the role of fixed clamping; the first polarization beam splitter prism (2) and the second polarization beam splitter prism (4) can freely rotate with the laser beam propagation direction as the axis. 2. A new type of high-precision laser energy/power attenuator according to claim 1, characterized in that a Faraday magnet is set between the first polarization beam splitter prism (2) and the second polarization beam splitter prism (4) The optical isolator (6) constitutes a magneto-optical isolation system; the magneto-optic isolator (6) is coaxial with the laser light emitted by the laser (1); the polarization rotation angle of the magneto-optic isolator (6) is 45°. 3. A new type of high-precision laser energy/power attenuator according to claim 1, characterized in that its working method is: turn on the laser output laser, place the energy meter or power meter in the laser output direction, and rotate the first A polarizing beam splitter (2) and a second polarizing beam splitting prism (4), until the output energy or power detected by the energy meter or power meter is approximately equal to the energy or power of the laser without an attenuator and is recorded as Emax, the fixed No. A polarizing beam splitter (2), marking the position S1 of the second polarizing beam splitting prism (4); then by rotating the second polarizing beam splitting prism (4), the laser output energy or power is 0, marking the position of the second polarizing beam splitting prism (4) S2; after that, the energy or power of the output laser can be continuously adjusted from Emax to 0 by rotating the second polarization beam splitter prism (4) between S1 and S2. 4. A new type of high-precision laser energy/power attenuator according to claim 3, characterized in that, after the attenuator is adjusted, the second polarization beam splitter prism (4) is at the position of S1, and the laser The output energy or power is Emax, the magneto-optic isolator (6) is placed between the first polarization beam splitter (2) and the second polarization beam splitter (4) to make it coaxial with the laser, and then the second polarization beam splitter is rotated The prism (4) makes the laser output energy reach Emax again, at this time, the second polarization beam splitter prism (4) is fixed to form a magneto-optical isolation system. 5. A new type of high-precision laser energy/power attenuator, characterized in that, for lasers of different wavelengths, the first polarization beam splitter prism (2) and the second polarization beam splitter prism (4) are coated with corresponding coating systems.