CN201697882U

CN201697882U - Device for detecting subsurface defects of optical elements

Info

Publication number: CN201697882U
Application number: CN2010202144029U
Authority: CN
Inventors: 李亚国; 雷向阳; 郑楠; 邓燕; 谢瑞清; 陈贤华; 王健; 许乔
Original assignee: CHENGDU FINE OPTICAL ENGINEERING RESEARCH CENTER
Current assignee: CHENGDU FINE OPTICAL ENGINEERING RESEARCH CENTER
Priority date: 2010-06-03
Filing date: 2010-06-03
Publication date: 2011-01-05
Anticipated expiration: 2020-06-03

Abstract

The utility model provides a device for detecting the subsurface defects of optical elements, having less measurement error. The device for detecting the subsurface defects of optical elements comprises a microscope, a precise displacement platform and an image data processing unit connected with the microscope, wherein a laser displacement sensor is also connected to the image data processing unit. By adopting the optical microscope and the laser displacement sensor to measure the subsurface defects, the device can simultaneously acquire the depths of the subsurface defects and the features of the subsurface defects under different depths, thereby realizing the observation on the features of the subsurface defects under different depths and the precise measurement on the depths and avoiding errors caused by repositioning the traditional detecting device, and the measurement precision is on the micron grade. The device not only can be used for detecting the subsurface defects of optical glass, but also be suitable for measuring the processing subsurface defects of engineering materials including ceramics, silicon, germanium and the like.

Description

The pick-up unit of subsurface defect of optical element

Technical field

The utility model relates to optics processing and detection range, particularly relates to a kind of pick-up unit that the optical element processing grinding stage produces subsurface defect that is used for.

Background technology

Along with the development of large laser optical system, astronomical telescope and space telescope system, more and more strict for the crudy requirement of optical element.For many years the optical element defect characteristics origin cause of formation be studies show that the subsurface defects such as micro-crack that produce in the optical element manufacture process are to cause the key factor of optical element defective.The life-span of the optical element in the optical system and performance are subjected to the especially influence of subsurface defect of its crudy.Therefore measure the degree and the degree of depth that subsurface defect of optical element produces accurately and efficiently, to optimize grinding and polishing process, raising working (machining) efficiency, to save processing cost significant, also provides the guidance foundation to the optical element that obtains the perfect surface of low defective simultaneously.

At present, mainly use for the measurement of subsurface defect of optical element and hit hole method or wedge surface polishing method and measure.This method is that the sample after will grinding earlier carries out the local polishing etching, utilize again contourgraph from the milling zone to the polishing area along certain direction, treating lateral areas field surface profile measures, obtain the pattern in tested zone, be the variation of degree of depth Z (highly) with X (level) direction, utilize microscope that the same area is observed again, must make the microscopic zone in full accord during observation with the contourgraph measured zone, and must know the coordinate of directions X, this relate to the microscopically sample relocate and microscope in the displacement accuracy problem of directions X, cause measurement result to introduce bigger error, cause finally that the degree of depth and topography measurement result's is unreliable.

The utility model content

Technical problem to be solved in the utility model provides the pick-up unit of the little subsurface defect of optical element of a kind of measuring error.

The technical scheme that the utility model technical solution problem is adopted is: the pick-up unit of subsurface defect of optical element, comprise microscope, precision displacement platform, the image data processing unit that is connected with microscope, on described image data processing unit, also be connected with laser displacement sensor.

The beneficial effects of the utility model are: the utility model adopts optical microscope and laser displacement sensor to carry out the measurement of subsurface defect, can obtain the subsurface defect pattern under the subsurface defect degree of depth and the different depth simultaneously, realized the observation of subsurface defect pattern under the different depth and the accurate measurement of the degree of depth, avoided traditional detection to reorientate the error of being introduced, measuring accuracy is in micron dimension; The utility model does not need expensive contourgraph, has avoided traditional measurement method problem, the problem includes: the measuring error that the problem that relocates causes has also been avoided the necessary strict corresponding harsh requirement of contourgraph measured zone and microscopic zone in the classic method; The utility model is for optimizing the grinding and the glossing of optical element, improve working (machining) efficiency, save process time and cost important quantification reference is provided, also provide important detection foundation simultaneously for obtaining low defective finished surface, the subsurface defect that the utility model not only can be used for optical glass detects, and is applicable to that equally also the processing subsurface defect of construction materials such as pottery, silicon, germanium is measured.

Description of drawings

Fig. 1 is the structural representation of the utility model device.

Embodiment

As shown in Figure 1, measurement mechanism of the present utility model comprises: microscope 1, laser displacement sensor 2, precision displacement platform 3, image data processing unit 4, image data processing unit 4 link together with microscope 1 and laser displacement sensor 2 respectively.Microscope 1 has the camera lens of high magnification large-numerical aperture and the camera lens of the wide visual field of low range, and wide visual field camera lens is used for the Primary Location in tested zone, and high-rate lens is used for accurate focusing and then measures the subsurface defect degree of depth and observation subsurface defect pattern.Laser displacement sensor 2 is used to measure the amount of movement of precision displacement platform 3 in the Z direction, and laser displacement sensor 2 has the above measuring accuracy of submicron order.Precision displacement platform 3 is used to place sample 5 and tested zone is accurately located, and precision displacement platform 3 can move on X and Z direction, and mobile accuracy is respectively submillimeter level and more than the micron order on X and the Z direction.Image data processing unit 41 image of gathering that is used to adjust the telescope to one's eyes carries out digital processing.

Above-mentioned data processing unit 4 can adopt common PC, and greater than 20mm, precision 0.1mm's precision displacement platform 3 beats in the Z direction ± 1 μ m at the directions X translation distance.Microscope 1 adopts the camera lens of high magnification (100 *) large-numerical aperture (NA=0.9) and the wide visual field of low range (5 *).Laser displacement sensor 2 can adopt the He-Ne laser of wavelength 632.8nm, and measuring accuracy 0.1 μ m realizes the depth survey of Z direction micron dimension.

Measuring method of the present utility model may further comprise the steps:

1) sample 5 after will grinding earlier carries out the local polishing etching;

2) sample 5 is placed on the precision displacement platform 3, adopts the low range camera lens of microscope 1 to determine initial observation area;

3) use high-rate lens instead and observe, mobile precision displacement platform 3 makes sample 5 move horizontally at directions X, makes high-rate lens be scanned up to polishing area to sample 5 gradually from abrasive areas;

4) when high-rate lens moves to required measurement regional, regulate precision displacement platform 3 along the Z direction, make the high-rate lens of microscope 1 focus on measured zone, utilize of the displacement of laser displacement sensor 2 record precision displacement platforms 3 simultaneously in the Z direction, this displacement is and is observed the degree of depth of zone with respect to the initial observation position, if this zone has subsurface defect, this displacement is the degree of depth of observation area subsurface defect so, observe the subsurface defect pattern of this position simultaneously by microscope 1, disposable pattern and the depth information that obtains subsurface defect under the different depth.

Claims

1. the pick-up unit of subsurface defect of optical element, comprise microscope (1), precision displacement platform (3), the image data processing unit (4) that is connected with microscope (1), it is characterized in that: on described image data processing unit (4), also be connected with laser displacement sensor (2).

2. the pick-up unit of subsurface defect of optical element as claimed in claim 1, it is characterized in that: described microscope (1) has the camera lens of high magnification large-numerical aperture and the camera lens of the wide visual field of low range.

3. the pick-up unit of subsurface defect of optical element as claimed in claim 1 is characterized in that: described laser displacement sensor (2) has the above measuring accuracy of submicron order.

4. the pick-up unit of subsurface defect of optical element as claimed in claim 1, it is characterized in that: described precision displacement platform (3) can move on X and Z direction, and mobile accuracy is respectively submillimeter level and more than the micron order on X and the Z direction.

5. the pick-up unit of subsurface defect of optical element as claimed in claim 1 is characterized in that: described image data processing unit (4) employing PC.