CN115077699A - High-resolution spectrometer - Google Patents

Abstract

The invention relates to a high-resolution spectrometer, which comprises a slit, a collimating objective lens, a light splitting element, an imaging objective lens and an area array detector which are sequentially arranged on a light path, wherein the array direction of the pixel array surface of the area array detector and the direction of the image of the slit on the focal plane of the imaging objective lens form a preset included angle, so that a plurality of pixels in the pixel array surface of the area array detector, which are nearly parallel to the direction of the image, in the array direction in a single row/line mode can respectively detect spectral lines with different wavelengths, and the defect that the spectral lines between adjacent single row/line pixels cannot be detected due to the fact that the spectral lines in the array direction in the pixel array surface of the area array detector, which are parallel to the direction of the image, in the existing spectrometer are effectively avoided; therefore, the resolution of the spectrograph is improved under the condition of not changing the resolution of the area array detector.

Description

A high-resolution spectrometer

technical field

The invention relates to the technical field of spectral analysis instruments, in particular to a high-resolution spectrometer.

Background technique

The spectrometer includes a slit, a collimating objective lens, a spectroscopic element, an imaging objective lens and a detector arranged in sequence on the optical path. The light emitted from the slit passes through the collimating objective lens to form parallel light, and the parallel light is split by the spectroscopic element. It is imaged onto the pixel array surface of the detector through the imaging objective lens. The spectral length of the spectrometer imaging is fixed, and the resolution of the spectrometer depends on the resolution of the detector. At present, to improve the resolution of the spectrometer, a high-resolution detector is used, but the high-resolution detector costs high, which directly leads to high Spectrometers with high resolution are expensive.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-resolution spectrometer to solve the above problems existing in the prior art.

The technical scheme that the present invention solves the above-mentioned technical problems is as follows:

A high-resolution spectrometer, characterized in that it includes a slit, a collimating objective lens, a spectroscopic element, an imaging objective lens and an area array detector sequentially arranged on an optical path, and light emitted from the slit passes through the collimating objective lens Then, parallel light is formed, the parallel light is split by the spectroscopic element, and the split light beam is imaged on the pixel array surface of the area array detector through the imaging objective lens, and the pixel array surface is set at the focal point of the imaging objective lens. A plane, and the array direction of the pixel array plane and the direction of the image of the slit on the focal plane of the imaging objective lens form a preset angle.

The beneficial effects of the present invention are: the array direction of the pixel array surface and the image direction of the slit on the focal plane of the imaging objective lens form a preset angle, so that the pixel array surface of the area array detector is nearly parallel to the image direction. Multiple pixels in a single column/row in a single direction detect spectral lines of different wavelengths respectively, which effectively avoids the detection of only one wavelength by multiple pixels in a single column/row in an array direction parallel to the direction of the image in the pixel array of the area array detector in the existing spectrometer. Spectral lines, the disadvantage that the spectral lines located between adjacent single-column/row pixels cannot be detected; thus, the resolution of the spectrometer can be improved without changing the resolution of the area array detector.

On the basis of the above technical solutions, the present invention can also be improved as follows.

Further, the preset angle is the angle between the pixel array plane and the direction of the image that is nearly parallel to the direction of the image and the direction of the image, and the preset angle is smaller than arctan(a/((n -1)*b));

Wherein, the a is the interval between adjacent pixels in the array direction that is nearly perpendicular to the image direction in the pixel array plane, and the b is the pixel array plane that is nearly parallel to the image direction. The interval between adjacent pixels in the array direction, where n is the number of pixels in the array direction that are nearly parallel to the image direction in the pixel array plane.

Further, the preset included angle is arctan(a/(n*b)).

Further, the light splitting element is a prism and/or a grating.

Another technical scheme of the present invention is as follows:

A film thickness meter, comprising the above-mentioned high-resolution spectrometer.

Another technical scheme of the present invention is as follows:

A coating machine includes the above-mentioned film thickness gauge.

Another technical scheme of the present invention is as follows:

An ellipsometer, comprising the above-mentioned high-resolution spectrometer.

Another technical scheme of the present invention is as follows:

A coating machine, comprising the above-mentioned ellipsometer.

Description of drawings

1 is a schematic diagram of the relative positional relationship between the pixel array surface and the image of the slit on the focal plane of the imaging objective lens in a high-resolution spectrometer of the present invention.

Detailed ways

The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples are only used to explain the present invention, but not to limit the scope of the present invention.

Embodiment 1 of the present invention is a high-resolution spectrometer, comprising a slit, a collimating objective lens, a spectroscopic element, an imaging objective lens, and an area array detector sequentially arranged on an optical path, and the light emitted from the slit passes through the collimating objective lens to form a parallel Light, parallel light is split by the spectroscopic element, and the split beam is imaged on the pixel array surface 1 of the area array detector through the imaging objective lens. The pixel array surface 1 is set on the focal plane of the imaging objective lens, and the array direction of the pixel array surface 1 is the same as The slit forms a preset angle in the direction of the image 2 of the focal plane of the imaging objective, as shown in FIG. 1 .

The array direction of the pixel array surface 1 includes the extension direction of a single column of pixels in the longitudinal direction, such as the BA direction shown in Figure 1, and the extension direction of a single row of pixels in the lateral direction, such as the AC direction shown in Figure 1. The two directions are perpendicular to each other. One of the directions can represent the array direction of the pixel array surface 1. It should be noted that the longitudinal direction and the lateral direction are respectively closer to the vertical line and the horizontal line. The direction of the image 2 of the slit in the focal plane of the imaging objective lens is characterized by the extending direction of the slit in the image 2 of the slit, such as the DC direction shown in FIG. 1 . Because the image 2 of the slit in the focal plane of the imaging objective lens is a series of mutually parallel images 2, each image 2 corresponds to a specific wavelength, and the wavelengths are continuous, that is, the image 2 is a spectrum with continuous wavelengths; the array of the pixel array surface 1 The direction and the direction of the image 2 of the focal plane of the imaging objective lens form a preset angle, so that the pixels in the pixel array plane 1 of the area array detector are nearly parallel to the direction of the image 2 in a single column/row of the array direction, respectively. Detecting spectral lines of different wavelengths, as shown in Figure 1, the array direction in the pixel array surface 1 that is nearly parallel to the direction of the image is the extension direction of a single column of pixels in the longitudinal direction, and multiple pixels in a single column detect spectral lines of different wavelengths respectively; effective; It is avoided that in the pixel array of the area array detector in the existing spectrometer, the array direction parallel to the direction of the image in a single column/row of multiple pixels only detects the spectral line of one wavelength, and the spectral line between adjacent single column/row pixels cannot be detected. Therefore, the resolution of the spectrometer can be improved without changing the resolution of the area array detector.

Embodiment 2 of the present invention is a high-resolution spectrometer. On the basis of Embodiment 1, the preset angle is the angle between the array direction in the pixel array plane 1 that is nearly parallel to the direction of the image 2 and the direction of the image 2. Let the included angle be less than arctan(a/((n-1)*b));

Among them, a is the interval between adjacent pixels in the array direction of the pixel array surface 1 that is nearly perpendicular to the direction of the image 2. As shown in Figure 1, the array direction of the pixel array surface 1 that is nearly perpendicular to the direction of the image 2 is the horizontal direction The extension direction of a single row of pixels in the direction, a is the interval between points A and C; b is the interval between adjacent pixels in the array direction in the pixel array surface 1 that is nearly parallel to the direction of the image 2, as shown in Figure 1, In the pixel array plane 1, the array direction that is nearly parallel to the direction of the image 2 is the extension direction of a single row of pixels in the longitudinal direction, and b is the interval between points A and E.

It should be noted that near-vertical and near-parallel are relative terms, and the array direction of the pixel array surface 1 includes the extension direction of a single column of pixels in the longitudinal direction and the extension direction of a single row of pixels in the lateral direction. There are two directions in total. The direction of the image 2 of the focal plane is determined. From the two array directions of the pixel array surface 1, the array direction that is closer to the direction of the image 2 is selected, that is, the direction of the pixel array surface 1 that is close to the perpendicular to the direction of the image 2. For the array direction, from the two array directions of the pixel array surface 1, the array direction that is more parallel to the direction of the image 2 is selected, that is, the array direction that is nearly parallel to the direction of the image 2 in the pixel array surface 1. In a specific implementation, the preset included angle is extremely small, and an array direction that is closer to parallel or closer to the perpendicular direction to the direction of the image 2 can be easily selected from the two array directions of the pixel array surface 1 .

n is the number of pixels in the array direction nearly parallel to the direction of the image in the pixel array surface (1), as shown in FIG.

As shown in Figure 1, ∠ABC=arctan(a/((n-1)*b)), when the preset angle is less than arctan(a/(((n-1)*b)), that is, the pixel detection at point B The spectral lines of the pixel array are located within ∠ABC, and the spectral lines detected by the three-point pixels A, B, and C are distributed in sequence according to the spectral direction. Each pixel in the 3rd column ... each pixel in the mth column, and each pixel in each column is used in sequence from top to bottom, so that the resolution of the spectrometer is the resolution m×n of the area array detector, and each pixel of the area array detector is used. It can be used in an orderly manner, where m is the number of pixels in a single row of pixels in the lateral direction of the pixel array surface 1, as shown in Figure 1, m=4; effectively avoiding the interference between the pixel array surface of the existing spectrometer and the image in the area array detector. A single column/row of multiple pixels in a parallel array direction only detects spectral lines of one wavelength, and the resolution of a spectrometer using an area array detector with a resolution of mXn is only m or n.

Embodiment 3 of the present invention is a high-resolution spectrometer. On the basis of Embodiment 2, the preset included angle is arctan(a/(n*b)).

As shown in Figure 1, let BD=b, then ∠ADC=arctan(a/(n*b)), when the preset angle is arctan(a/(n*b)), that is, the spectrum detected by the C point pixel The line passes through point D, and since BD=b, that is, the interval between BD is equal to the interval between adjacent pixels in the longitudinal direction, the spectral interval between the spectral lines detected by the pixels at points B and C is adjacent to the longitudinal direction. The spectral interval between the spectral lines detected by the pixels is equal, so that the spectral interval between the spectral lines detected by the two pixels used in sequence according to the spectral direction is equal; as shown in Figure 1, the pixels of the area array detector with a resolution of 4X4 Among the 16 spectral lines detected by the 16 pixels in the array surface 1, the spectral intervals between adjacent spectral lines are equal.

Embodiment 4 of the present invention is a high-resolution spectrometer. On the basis of any of Embodiments 1 to 3, the spectroscopic element is a prism and/or a grating.

Embodiment 5 of the present invention is a film thickness meter, including the high-resolution spectrometer in any of Embodiments 1 to 4.

Embodiment 6 of the present invention is a coating machine, including the film thickness gauge in Embodiment 5.

Embodiment 7 of the present invention is an ellipsometer, including the high-resolution spectrometer in any of Embodiments 1 to 4.

Embodiment 8 of the present invention is a coating machine, including the ellipsometer in Embodiment 7.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

1. The utility model provides a high resolution spectrometer, its characterized in that is including setting gradually slit, collimating objective, beam splitting component, formation of image objective and the area array detector on the light path, follows the light of slit outgoing passes through form the parallel light behind the collimating objective, the parallel light passes through beam splitting component beam splitting, light beam process after the beam splitting the formation of image objective is arrived on the pixel array face (1) of area array detector, pixel array face (1) sets up the focal plane of formation of image objective, just the array direction of pixel array face (1) with the slit is in the direction of formation of image (2) of the focal plane of formation of image objective becomes to predetermine the contained angle.

2. The high resolution spectrometer according to claim 1, wherein the predetermined angle is an angle between an array direction of the pixel array plane (1) approximately parallel to the direction of the image (2) and the direction of the image (2), the predetermined angle being smaller than arctan (a/((n-1) × b));

wherein a is an interval between adjacent pixels in an array direction approximately perpendicular to the direction of the image (2) in the pixel array surface (1), b is an interval between adjacent pixels in the array direction approximately parallel to the direction of the image (2) in the pixel array surface (1), and n is the number of pixels in the array direction approximately parallel to the direction of the image (2) in the pixel array surface (1).

3. The high resolution spectrometer according to claim 2, wherein the predetermined angle is arctan (a/(n × b)).

4. The high resolution spectrometer according to any of claims 1 to 3, wherein the beam splitting element is a prism and/or a grating.

5. A film thickness gauge comprising the high resolution spectrometer of any one of claims 1 to 4.

6. A coater comprising the film thickness measuring instrument according to claim 5.

7. An ellipsometer comprising the high resolution spectrometer of any one of claims 1 to 4.

8. A coater comprising the ellipsometer of claim 7.

Images