Disclosure of Invention
Aiming at the defects or the improvement requirements of the prior art, the invention provides a laser point-to-point transmission system, which is used for solving the technical problem of low accuracy when the traditional reflecting galvanometer system carries out point-to-point transmission.
In order to achieve the above object, the present invention provides a laser peer-to-peer transmission system, comprising: the collimating lens, the first optical wedge and the second optical wedge are sequentially arranged along the direction of the light path;
the refraction edges of the first optical wedge and the second optical wedge are vertical; the rotating angles of the first optical wedge and the second optical wedge are determined according to the target position; the rotating shaft of the first optical wedge, the rotating shaft of the second optical wedge and the optical axis are mutually vertical in pairs;
the laser collimated by the collimating lens is deflected by the first optical wedge and the second optical wedge in sequence and is focused to a target position, so that point-to-point transmission is realized.
Further preferably, the laser point-to-point transmission system further includes: a first motor and a second motor;
the first motor is connected with the first optical wedge and used for driving the first optical wedge to rotate;
and the second motor is connected with the second optical wedge and is used for driving the second optical wedge to rotate.
Further preferably, the laser point-to-point transmission system further includes: a rotation control module; the rotation control module is respectively connected with the first motor and the second motor;
and the rotation control module is used for determining the deflection angles required by the first optical wedge and the second optical wedge based on the target position information, converting the deflection angles into control signals of the first motor and the second motor, and inputting the control signals into the first motor and the second motor respectively.
Further preferably, the laser point-to-point transmission system further includes: the first reflector and the second reflector are sequentially arranged behind the second optical wedge along the optical path direction, and the third motor is correspondingly connected with the first reflector and the fourth motor is correspondingly connected with the second reflector; wherein the rotation axis of the first reflector is parallel to the rotation axis of the first optical wedge; the rotation axis of the second reflector is parallel to the rotation axis of the second wedge;
the rotation control module is also used for determining the deflection angles required by the first reflecting mirror and the second reflecting mirror based on the target position information, converting the deflection angles into control signals of a third motor and a fourth motor, and inputting the control signals into the third motor and the fourth motor respectively;
the third motor is used for driving the first reflector to rotate under the control action of a control signal of the third motor;
the fourth motor is used for driving the second reflector to rotate under the control action of the control signal of the fourth motor;
the first mirror and the second mirror are used to increase the range of laser deflection.
Further preferably, the third motor and the fourth motor are galvanometer motors.
Further preferably, in order to make the deflection range of the motor utilized to the maximum extent, the initial included angle between the normal of the incidence plane of the first optical wedge and the optical axis is greater than or less than the incidence angle corresponding to the minimum deflection angle of the first optical wedge; the initial included angle between the normal of the incidence surface of the second optical wedge and the optical axis is larger than or smaller than the incidence angle corresponding to the minimum deviation angle of the second optical wedge.
Further preferably, the initial included angle between the normal of the incidence plane of the first optical wedge and the second optical wedge and the optical axis is set as the corresponding included angle when the laser deflection is located at the center of the required laser deflection range; when the first optical wedge or the second optical wedge is positioned at the boundary of the working range, the incident angle of the laser is still larger than or smaller than the incident angle corresponding to the minimum deviation angle of the first optical wedge or the second optical wedge.
Further preferably, the incident surface and the exit surface of the first optical wedge and the second optical wedge are both plated with antireflection films, and the incident surface and the exit surface are plated with corresponding antireflection films according to the angle ranges of laser incidence and laser exit, so as to reduce the loss of laser energy caused by reflection.
Further preferably, the first motor and the second motor are galvanometer motors.
Further preferably, the laser point-to-point transmission system further includes: a fifth motor;
and the fifth motor is connected with the collimating mirror and used for controlling the collimating mirror to move along the optical axis so as to adjust the position of the collimating mirror, thereby focusing the laser at the target position.
Further preferably, the fifth motor is a flat plate type linear motor, a U-shaped slot type linear motor or a cylindrical type linear motor.
Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:
1. the invention provides a laser point-to-point transmission system, which comprises a first optical wedge and a second optical wedge, wherein a rotating shaft of the first optical wedge, a rotating shaft of the second optical wedge and an optical axis are mutually vertical in pairs; the rotating angles of the first optical wedge and the second optical wedge are determined according to the target position, so that laser deflects along two mutually perpendicular directions and is focused to the target position to realize point-to-point transmission; the optical wedge can finely adjust the deflection angle of the laser during emission when rotating, the laser deflection angle change amount is far smaller than the optical wedge deflection angle change amount, the optical wedge is controlled by a motor to deflect, the precision of small-angle control of the laser can be effectively improved, and high-precision laser point-to-point transmission is achieved.
2. The laser point-to-point transmission system provided by the invention integrates two deflection modes of the optical wedge and the reflector, and the optical wedge and the reflector are matched for use, so that the precision of small-angle control of laser is increased, and the precision of large-angle control is also improved.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
To achieve the above object, the present invention provides a laser peer-to-peer transmission system, as shown in fig. 1, including: the collimating lens 2, the first optical wedge 4 and the second optical wedge 6 are sequentially arranged along the direction of the light path; the center points of the collimating lens 2, the first optical wedge 4 and the second optical wedge 6 are all positioned on an optical axis;
the refraction edges of the first optical wedge and the second optical wedge are vertical; the rotating angles of the first optical wedge and the second optical wedge are determined according to the target position; specifically, a space spherical coordinate system is established by taking the system as an origin through the space position of the target position, the angle of the azimuth angle and the pitch angle of the laser to be changed is calculated, and the rotating angle of the first optical wedge and the second optical wedge is calculated according to the relation between the rotating angle of the optical wedge and the laser deflection angle. The rotating shaft of the first optical wedge, the rotating shaft of the second optical wedge and the optical axis are mutually vertical in pairs; because the refraction edges of the two optical wedges are parallel to the rotating shafts of the two optical wedges, the rotating shafts are not influenced by the rotating operation, and the rotating shafts of the two optical wedges are mutually vertical, the refraction edges of the two optical wedges are still vertical in the rotating process. Specifically, the first motor and the second motor may be galvanometer motors;
the laser collimated by the collimating lens is deflected by the first optical wedge and the second optical wedge in sequence and is focused to a target position, so that point-to-point transmission is realized. Preferably, the incident surface and the exit surface of the first optical wedge and the second optical wedge are both plated with antireflection films, and the incident surface and the exit surface are plated with corresponding antireflection films according to the angle ranges of laser incidence and laser exit, so as to reduce the loss of laser energy caused by reflection.
The optical wedge is a device for controlling the deflection angle of laser light by utilizing the refraction phenomenon of light at two medium interfaces with small included angles; the optical wedge can finely adjust the deflection angle of the laser during emission when rotating, the laser deflection angle change amount is far smaller than that of the optical wedge, the deflection of the optical wedge is controlled by a motor, and the laser angular control with higher precision than that of the reflector control can be realized.
Preferably, in some optional embodiments, the laser-to-point transmission system further includes: a first motor and a second motor;
the first motor is connected with the first optical wedge and used for driving the first optical wedge to rotate; and the second motor is connected with the second optical wedge and is used for driving the second optical wedge to rotate. Specifically, the first motor and the second motor may be galvanometer motors.
Further, the above laser point-to-point transmission system further includes: a rotation control module; the rotation control module is respectively connected with the first motor and the second motor;
the rotation control module is used for calculating the angle required to be changed by the azimuth angle and the pitch angle of the laser based on the target position information, further determining the deflection angle required by the first optical wedge and the second optical wedge according to the relation between the optical wedge rotation angle and the laser deflection angle, converting the deflection angle into control signals of the first motor and the second motor, and inputting the control signals into the first motor and the second motor respectively.
Further, the above laser point-to-point transmission system further includes: the first reflector and the second reflector are sequentially arranged behind the second optical wedge along the optical path direction, and the third motor is correspondingly connected with the first reflector and the fourth motor is correspondingly connected with the second reflector; wherein the rotation axis of the first reflector is parallel to the rotation axis of the first optical wedge; the rotation axis of the second reflector is parallel to the rotation axis of the second wedge;
the rotation control module is also used for determining the deflection angles required by the first reflecting mirror and the second reflecting mirror based on the target position information, converting the deflection angles into control signals of a third motor and a fourth motor, and inputting the control signals into the third motor and the fourth motor respectively;
the third motor is used for driving the first reflector to rotate under the control action of a control signal of the third motor; the fourth motor is used for driving the second reflector to rotate under the control action of the control signal of the fourth motor; the third motor and the fourth motor may be galvanometer motors.
The first mirror and the second mirror are used to increase the range of laser deflection.
It should be noted that, when the required laser angle deflection is large, the laser can be deflected to the required angle roughly by using the mirror, and the advantage of the small angle control of the optical wedge is combined to be controlled finely, so as to increase the working range of the system.
Preferably, the laser peer-to-peer transmission system further includes: a fifth motor; and the fifth motor is connected with the collimating mirror and used for controlling the collimating mirror to move along the optical axis so as to adjust the position of the collimating mirror, thereby focusing the laser at the target position. The fifth motor may be a flat-plate linear motor, a U-shaped slot linear motor, a cylindrical linear motor (voice coil motor), or the like.
FIG. 2 is a schematic diagram of laser deflection by an optical wedge, where α is the wedge angle of the optical wedge, n is the refractive index of the optical wedge, and I is1Is the incident angle, l ', of the laser light on the incident surface (first refractive surface)'1Is the angle of refraction of the laser light at the incident surface (first refraction surface) — I2Is an incident angle of laser light on an emission surface (second refractive surface) — I'2Is the angle of refraction of the laser light at the exit surface (second refractive surface). Delta is the included angle between the laser of the incident optical wedge and the laser of the emergent optical wedge, namely the deflection angle of the laser.
From the law of refraction of light and the angular relationship, the above parameters satisfy the following formula.
When I is1=I2The minimum deflection angle δ of the laser beam is recorded as the minimum deflection angle δ of the laser beammin(i.e., the minimum deflection angle of the wedge), wherein the incident angle of the laser beam on the incident surface is I0。
The angle of incidence I of the laser beam is used since the angle of rotation of the optical wedge is equal to the angle of change of the angle of incidence of the laser beam1A mathematical model of the rotation of the optical wedge to the deflection of the laser can be established as a variable, and when the angle of the optical wedge is very small and the incident angle of the laser is very close to the incident angle of the minimum deflection angle, the following approximate formula is provided:
taking a quartz glass (refractive index of 1.46) having a wedge angle of 10 ° (174.53mrad) as an example, the minimum deviation angle of the laser light was calculated to be 80.65mrad, at which time the incident angle I was1127.59 mrad. The optical wedge is rotated by 1mrad at an incident angle I1As shown in fig. 3, a graph showing the relationship between the laser deflection angle and the wedge deflection angle was constructed with an output laser deflection angle of 68.62nrad being 128.59mrad, the abscissa being the difference between the rotation angle of the wedge and the rotation angle of the wedge corresponding to the minimum laser deflection angle, and the ordinate being the difference between the laser deflection angle and the minimum laser deflection angle. FIG. 4 is a schematic diagram of an optical wedge deflected laser provided by the present invention, which shows different effects of the optical wedge on the laser angle when the single optical wedge works in three states, i.e., the center position, the lower boundary of the working range, and the upper boundary of the working range. As can be seen from fig. 3 and 4, the precision of the small-angle control of the laser can be effectively improved by using the optical wedge deflection.
As can be seen from fig. 3, in order to expand the working range of the system and take into account the working accuracy, the initial rotation angle of the optical wedge should deviate from the rotation angle that minimizes the laser deflection, and is selected according to the actual situation. Specifically, in order to make the maximum use of the deflection range of the motor, in some optional embodiments, the initial included angle between the normal of the incident surface of the first optical wedge and the optical axis is greater than or less than the incident angle corresponding to the minimum deflection angle of the first optical wedge; the initial included angle between the normal of the incidence surface of the second optical wedge and the optical axis is larger than or smaller than the incidence angle corresponding to the minimum deviation angle of the second optical wedge. Preferably, the initial included angles between the normal lines of the incident surfaces of the first optical wedge and the second optical wedge and the optical axis are both such that the initial laser deflection is located at the center of the required laser deflection range, and the initial included angles between the normal lines of the incident surfaces of the first optical wedge and the second optical wedge and the optical axis are set as the included angles corresponding to the laser deflection located at the center of the required laser deflection range. When the first optical wedge or the second optical wedge is positioned at the boundary of the working range, the incident angle of the laser is still larger than or smaller than the incident angle corresponding to the minimum deviation angle of the first optical wedge or the second optical wedge.
In order to further explain the laser point-to-point transmission system provided by the present invention, the following detailed description is made with reference to the embodiments:
examples of the following,
As shown in fig. 5, the laser peer-to-peer transmission system in this embodiment includes: the laser device comprises a laser 1, a collimating mirror 2, a voice coil motor 3 for controlling the movement of the collimating mirror 2, a first optical wedge 4, a first mirror vibrating motor 5 for controlling the rotation of the first optical wedge 4, a second optical wedge 6 and a second mirror vibrating motor 7 for controlling the rotation of the second optical wedge 6.
In use, laser light emitted by the laser 1 is incident on the collimating mirror 2; the collimating mirror 2 is controlled by a voice coil motor, so that the collimating mirror moves along an optical axis to adjust the position of the collimating mirror, and laser is focused to a target position. The first optical wedge 4 and the second optical wedge 6 control the change of the azimuth angle and the pitch angle of the laser, respectively. And antireflection coatings are plated on two surfaces of the optical wedge so as to reduce the loss of laser energy caused by reflection. In order to expand the working range and take the working precision into consideration, the initial rotation angle of the optical wedge deviates from the optical wedge rotation angle which enables the laser to deflect the minimum, and the optical wedge rotation angle is selected according to the actual situation. For example, as shown in fig. 2, the optical wedge is selected, the galvanometer motor with the minimum stroke of 10urad is selected, the working range is ± 1mrad, and for the convenience of the control relationship approaching linearity, the working range of the optical wedge is selected as shown in fig. 3, the initial placement mode of the optical wedge needs to make the laser incident angle equal to the incident angle corresponding to the center of the required working range, i.e., +261mrad, and the emergent light direction at this time is taken as the reference axis. When in use, the galvanometer motor is utilized to control the optical wedge to rotate, so that the incidence angle range of the laser is controlled within 0.182rad-0.303rad, the laser can deflect within the range of +/-1 mrad relative to the reference shaft, and the small-angle control precision of the laser is effectively improved. The target is quickly and precisely aligned through optical wedge deflection, and laser point-to-point transmission with higher precision is realized.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.