阅读说明：本技术 一种波前提取算法及采用该算法的剪切干涉仪 (A kind of wavefront extraction algorithm and the shearing interferometer using the algorithm ) 是由 林亮 郭春雷 于 2018-05-23 设计创作，主要内容包括：本发明涉及光学测量领域,具体涉及一种波前提取算法及采用该算法的剪切干涉仪,其算法将x坐标的相位差分成第一奇数阶项和第一偶数阶项,再分别计算出x坐标波前的偶阶项和奇阶项,最后与y轴的波前计算总和既可以得到波前,有效的简化了提取流程；其相应的剪切干涉仪也仅通过一个分束立方体调节待测光束的相移,实现了超快光束波前的提取,简化了仪器结构,使得对激光光束的波前提取更为简单。(The present invention relates to field of optical measurements, more particularly to a kind of wavefront extraction algorithm and using the shearing interferometer of the algorithm, its algorithm is by the phase difference of x coordinate at the first odd-order item and the first even order terms, the even order item and odd order item of x coordinate wavefront are calculated separately out again, finally with the wavefront calculations summation of y-axis both available wavefront, extraction process is effectively simplified；Its corresponding shearing interferometer also only adjusts the phase shift of light beam to be measured by a beam-dividing cube, realizes the extraction of ultrafast Beam Wave-Front, simplifies apparatus structure, so that extracting to the wavefront of laser beam more simple.)

1. a kind of wavefront extraction algorithm, which comprises the following steps:

S1. the phase difference of the x coordinate of light beam to be measured is extracted；

S2. by the phase difference of the x coordinate at the first odd-order item and the first even order terms；

S3. the x coordinate even order item that wavefront is calculated by the first odd-order item calculates wavefront by first even order terms X coordinate odd order item；

It S4. is the wavefront of y-axis by the phase difference calculating shear direction that shear direction is y-axis；

S5. the summation of the x coordinate even order item of the wavefront and the x coordinate odd order item of the wavefront and the wavefront of the y-axis is calculated.

2. algorithm according to claim 1, which is characterized in that the step S4 includes:

S41. the phase difference that the light beam shear direction to be measured is y-axis is extracted；

S42. by the shear direction be y-axis phase difference at the second odd-order item and the second even order terms；

S43. the y-coordinate even order item that wavefront is calculated by the second odd-order item calculates wave by second even order terms Preceding y-coordinate odd order item；

S44. the summation of the y-coordinate even order item of the wavefront and the y-coordinate odd order item of the wavefront is calculated.

3. algorithm according to claim 1, which is characterized in that further comprising the steps of after the step S1:

S11. phase unwrapping is carried out to the phase difference of the x coordinate.

4. algorithm according to claim 3, which is characterized in that further comprising the steps of after the step S11:

S12., solution is twined to the phase difference fitting Zernike Polynomials of the x coordinate of completion.

5. algorithm according to claim 1, which is characterized in that the front and back of the step S1 is further comprising the steps of:

Q1. using pi/2 as the increment of phase shift, shearing interferometer in phase shift optical path makes light beam to be measured generate interference pattern；

Q2. the phase difference of the x coordinate of the light beam to be measured is extracted by the beam intensity summation of the interference pattern.

6. algorithm according to claim 5, which is characterized in that the phase shift is to translate along the y-axis direction, time of the phase shift Number is 4 times.

7. a kind of shearing interferometer for being applicable in any one of claim 1-6 wavefront extraction algorithm, including beam-dividing cube with And the imaging device being connect with the beam-dividing cube optical path, which is characterized in that further include the tune for supporting the beam-dividing cube Control bracket；The posture of the beam-dividing cube is controlled by the regulation bracket.

8. shearing interferometer according to claim 7, which is characterized in that the regulation bracket include three-dimensional tilt module and Three-dimensional mobile module.

9. shearing interferometer according to claim 8, which is characterized in that further include being arranged in light source and the beam splitting cube Filter between the optical path of body.

10. shearing interferometer according to claim 7, which is characterized in that the imaging device includes ccd imager and shows Show device；The display is electrically connected with the ccd imager and shows interference image thereon.

Technical field

The present invention relates to field of optical measurements, in particular to a kind of wavefront extraction algorithm and cutting using the algorithm Shearing interferometer.

Background technique

Wavefront measurement technology and wavefront extraction algorithm play in fields such as modern physics, biomedicine and engineering technology Increasingly important role.Especially in beam collimation measurement, optical system wavefront aberration measurement and optical element surface face shape The fields such as measurement have important practical value.Especially when realizing that ultrafast Beam Wave-Front is extracted, ultrafast light beam such as femtosecond laser Light path it is short, stimulating frequency is high, extracted after Yao Shixian light beam is relevant wavefront difficulty is considerably complicated and corresponding shearing interferometer Close structure is complicated, and technology difficulty is big.

As it can be seen that its calculating step of existing wavefront extraction algorithm is relatively complicated, relevant shear interferometer structure and optical path device Part is also accurate complicated, is difficult intuitive and easy realization wavefront and extracts.Therefore existing technology Shortcomings.

Summary of the invention

The embodiment of the invention provides wavefront extraction algorithm and shearing interferometers, solve at least current wavefront extraction algorithm The complex technical problem with wavefront measurement apparatus structure.

In order to solve the above-mentioned technical problems, the present invention provides a kind of wavefront extraction algorithms, comprising the following steps:

S1. the phase difference of the x coordinate of light beam to be measured is extracted；

S2. by the phase difference of the x coordinate at the first odd-order item and the first even order terms；

S3. the x coordinate even order item that wavefront is calculated by the first odd-order item, is calculated by first even order terms The x coordinate odd order item of wavefront；

It S4. is the wavefront of y-axis by the phase difference calculating shear direction that shear direction is y-axis；

S5. the wavefront of the x coordinate even order item of the wavefront and the x coordinate odd order item and y-axis of the wavefront is calculated Summation.

Preferably, the step S4 includes:

S41. the phase difference that the light beam shear direction to be measured is y-axis is extracted；

S42. by the shear direction be y-axis phase difference at the second odd-order item and the second even order terms；

S43. the y-coordinate even order item that wavefront is calculated by the second odd-order item, passes through the second even order terms meter Calculate the y-coordinate odd order item of wavefront；

S44. the summation of the y-coordinate even order item of the wavefront and the y-coordinate odd order item of the wavefront is calculated.

Preferably, further comprising the steps of after the step S1:

S11. phase unwrapping is carried out to the phase difference of the x coordinate.

Preferably, further comprising the steps of after the step S11:

S12., solution is twined to the phase difference fitting Zernike Polynomials of the x coordinate of completion.

Preferably, the front and back of the step S1 is further comprising the steps of:

Q1. using pi/2 as the increment of phase shift, shearing interferometer in phase shift optical path makes light beam to be measured generate interference pattern；

Q2. the phase difference of the x coordinate of the light beam to be measured is extracted by the beam intensity summation of the interference pattern.

Preferably, the phase shift is to translate along the y-axis direction, and the number of the phase shift is 4 times.

In order to solve the above-mentioned technical problem, cutting for above-mentioned any one wavefront extraction algorithm is applicable in the present invention also provides a kind of Shearing interferometer, including beam-dividing cube and the imaging device being connect with the beam-dividing cube optical path, which is characterized in that also wrap Include the regulation bracket for supporting the beam-dividing cube；The posture of the beam-dividing cube is controlled by the regulation bracket.

Preferably, the regulation bracket includes three-dimensional tilt module and three-dimensional mobile module.

It preferably, further include the filter being arranged between light source and the optical path of the beam-dividing cube.

Preferably, the imaging device includes ccd imager and display；The display and ccd imager electricity It connects and shows interference image thereon.

In embodiments of the present invention by the phase difference of x coordinate at the first odd-order item and the first even order terms, then distinguish Calculate the even order item and odd order item of x coordinate wavefront, finally with the wavefront calculations summation of y-axis both available wavefront, effectively Extraction process is simplified, corresponding shearing interferometer also only adjusts the phase shift of light beam to be measured by a beam-dividing cube, letter Ultrafast Beam Wave-Front is changed and has extracted apparatus structure, so that being extracted to the wavefront of laser beam more simple.

Detailed description of the invention

The drawings described herein are used to provide a further understanding of the present invention, constitutes part of this application, this hair Bright illustrative embodiments and their description are used to explain the present invention, and are not constituted improper limitations of the present invention.In the accompanying drawings:

Fig. 1 is the main flow schematic diagram of wavefront extraction algorithm of the present invention；

Fig. 2 is the structural schematic diagram of shearing interferometer of the present invention；

Fig. 3 is the structural schematic diagram of the shearing interferometer of single optical element in the prior art.

Specific embodiment

In order to enable those skilled in the art to better understand the solution of the present invention, below in conjunction with the attached of description of the invention Fig. 1-attached drawing 3, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only It is only the embodiment of a part of the invention, instead of all the embodiments.Based on the embodiments of the present invention, the common skill in this field Art personnel every other embodiment obtained without making creative work all should belong to what the present invention protected Range.

It should be noted that description and claims of this specification and term " first " in above-mentioned attached drawing, " Two " etc. be to be used to distinguish similar objects, without being used to describe a particular order or precedence order.It should be understood that using in this way Data be interchangeable under appropriate circumstances, so as to the embodiment of the present invention described herein can in addition to illustrating herein or Sequence other than those of description is implemented.In addition, term " includes " and " having " and their any deformation, it is intended that cover Covering non-exclusive includes to be not necessarily limited to for example, containing the process of a series of steps or units, algorithm, system, product or equipment Step or unit those of is clearly listed, but may include be not clearly listed or for these processes, algorithm, product Or other step or units that equipment is intrinsic.

As shown in Fig. 3, existing shearing interferometer is constituted using single optical element, can extract wavefront, is interfered The optical path difference of light beam isBut a+by will not inswept 0, equipment cannot be used for ultrafast light beam.Have more multiple Miscellaneous shearing interferometer configuration can make a+by inswept 0.But there are currently no single optical elements to accomplish.

Specifically, because the temporal coherence of ultrafast light beam is very short (there was only several femtoseconds under normal conditions), the prior art The optical path difference of optical element can not inswept 0 two ultrafast light beam substantially will not interfere with, therefore the shearing interferometer of the prior art It is the wavefront that can not extract ultrafast light beam.As it can be seen that the shearing interferometer of existing single optical element is not capable of measuring ultrafast light beam Wavefront.