CN105067119A - Field-of-view segmentation interference imaging spectrometer and imaging method - Google Patents

Abstract

The invention provides a field of view segmentation interference imaging spectrometer, comprising a telescopic objective lens, a field of view segmentation prism, an interferometer I, an interferometer II, a collimator lens I, a collimator lens II, a Fourier transform lens I and a Fourier transform lens. Transformation lens 2, the field of view splitting prism is a sharp-angle reflective prism, which is set at the image surface of the telescopic objective lens, and the apex of the field of view splitting prism is located at the optical axis of the telescopic objective lens; the light from the telescopic objective lens is divided by the field of view The two reflective surfaces of the prism are reflected as two reflected light rays, which enter the interferometer one and the interferometer two through the collimator lens one and the collimator lens two respectively; the Fourier transform lens one and the Fourier transform lens two are arranged in the interferometer In the optical path of the outgoing light of the first and interferometer two. The two fields of view formed by the invention are respectively used in different spectral ranges, the utilization rate of the field of view of the optical system is high, and the signal-to-noise ratio of the system is high.

Description

Field-of-view segmentation interference imaging spectrometer and imaging method

technical field

The invention relates to a spectrometer, in particular to a field-of-view division interference imaging spectrometer and an imaging method thereof which can be applied in a space-time joint modulation interference imaging spectrometer.

Background technique

The optical system of the space-time joint modulation interference imaging spectroscopy technology consists of an interferometer and a Fourier transform lens. High-resolution spatio-temporal joint modulation interference imaging spectrometer In order to reduce the volume and weight of the interferometer, a telescopic system with a compressed aperture (composed of a telescopic objective lens and a collimating lens) is added in front of the interferometer, as shown in Figure 1. The field of view of space-time joint modulation interference imaging spectroscopy technology is generally a rectangular field of view, which is divided into spectral direction and spatial direction. The length of the spectral direction is generally much smaller than the length of the spatial direction, while the optical system design field of view is generally a circular field of view. At this time, the spectral direction of the interference imaging spectrometer does not fully utilize the field of view of the optical system.

Large and wide interferometric imaging spectrometers are limited by the area array of detectors and require detector splicing. As shown in Figure 2, due to the existence of the detector mechanical frame, seamless splicing cannot be directly performed. The traditional method of splitting and splicing by prism splits the light energy into two and connects to the subsequent detectors respectively, which reduces the light energy entering each detector, thereby reducing the signal-to-noise ratio of the interference imaging spectrometer.

Contents of the invention

The technical problem to be solved by the present invention is to provide a field-of-view segmentation interference imaging spectrometer with high field-of-view utilization of the optical system, and at the same time provide a seamless field-of-view splicing method without energy loss for interference-type hyperspectral imaging instruments.

A field of view segmentation interference imaging spectrometer provided by the present invention includes a telescopic objective lens, a field of view segmentation prism, a collimator lens 1, a collimator lens 2, an interferometer 1, an interferometer 2, a Fourier transform lens 1 and a Fourier transform lens. Lie transform lens 2 is special in that: the field of view splitting prism is a sharp-angle reflective prism, which is set at the image plane of the telescopic objective lens, and the apex of the field of view splitting prism is located at the optical axis of the telescopic objective lens; The light from the far objective lens is reflected by the two reflective surfaces of the field-of-view splitting prism into two paths of reflected light, which enter interferometer one and interferometer two through collimator lens one and collimator lens two respectively; Fourier transform lens one and Fourier transform lens one The second leaf transformation lens is arranged in the optical path of the outgoing light of the first interferometer and the second interferometer.

Field of view segmentation interference imaging method provided by the present invention

Its special feature is that it includes the following steps:

1) The telephoto objective converts the light from the target into converging light, which is imaged at the image plane of the telescopic objective;

2) The field of view splitting prism located at the mirror surface of the telescopic objective mirrors the converging light rays of the telescopic objective lens along the spectral direction into two beams of divergent light rays, one up and one down, through two reflective surfaces;

3) The collimating lens 1 and the collimating lens 2 respectively convert the two beams of divergent rays into two beams of parallel rays, and then the two beams of parallel rays enter the first interferometer and the second interferometer respectively;

4) The outgoing rays of interferometer 1 and interferometer 2 are respectively received by respective detectors through Fourier transform lens 1 and Fourier transform lens 2;

5) When the field of view is divided, adjust the optical axes of collimator lens 1 and collimator lens 2 respectively, so that they are in the same direction as the chief ray of a suitable off-axis field of view of the telescopic objective lens after being reflected by the field of view division prism Coincident, to complete the match;

6) During system push-broom imaging, the two sets of interferometric systems after the field of view are divided scan the target successively, and the time difference is related to the two off-axis field of view chief rays selected in step 5).

The beneficial effects of the present invention are:

1) Utilizing the characteristics of the spectrometer’s rectangular field of view (the spectral direction is smaller than the spatial direction), at the primary image plane of the system, a sharp-angled reflective prism is used to segment the field of view. Advanced interference imaging spectral detection system, the two fields of view formed are respectively used in different spectral ranges, the utilization rate of the field of view of the optical system is high, and the signal-to-noise ratio of the system is high;

2) Using the field-of-view cutting interference imaging spectroscopy technology, the field of view is divided into two along the spectral direction by the field-of-view splitting prism and then led to the subsequent system through reflection. The right side of the field of view is used for the second detector, which realizes the seamless field of view splicing without energy loss of the interference imaging spectroscopy technology.

Description of drawings

Figure 1 is a schematic diagram of an interference imaging spectrometer;

Figure 2 is the relationship between the effective field of view of the interference imaging spectrometer and the field of view of the optical system;

Fig. 3 is the schematic diagram of the field of view segmentation interference imaging spectrometer of the present invention;

Fig. 4 is a schematic diagram of one of the application examples of the present invention;

Fig. 5 is a schematic diagram of the seamless field of view stitching without energy loss using the field-of-view segmentation imaging spectroscopy technique.

Detailed ways

As shown in FIG. 3 , the present invention adds a field of view splitting prism 2 at the primary image plane of the telescopic objective lens 1 , and the apex angle of the field of view splitting prism 2 determines the spatial position allocation of the subsequent system.

After the field of view is divided, the light is reflected by the two reflective surfaces of the field of view splitting prism into two lines of light, one of which is collimated by the collimating lens 3 and then enters the interferometer 5 and the Fourier transform lens 7; The light is collimated by collimating lens 2 4 and enters interferometer 2 6 and Fourier transform lens 2 8; Fourier transform lens 1 7 and Fourier transform lens 2 8 are respectively received by their respective detectors.

When the field of view is divided, the optical axes of collimating mirror 1 and collimating mirror 2 need to be adjusted separately so that they coincide with the direction of the chief ray of a certain off-axis field of view of the telescopic objective lens after being reflected by the field of view splitting prism.

When the system pushes broom imaging, the two sets of interference systems after the field of view are divided scan the target successively, and the time difference is related to the off-axis chief ray of the telescopic objective lens selected when the optical axes of collimator 1 and collimator 2 are adjusted.

The field of view segmentation interference imaging spectrum technology of the present invention utilizes the characteristics of the rectangular field of view (the spectral direction is smaller than the spatial direction) of the spectrometer. At the primary image plane of the system, a sharp-angle reflective prism is used to segment the field of view. Each field of view channel can be respectively connected to the subsequent interference imaging spectrum detection system, and its optical path is shown in Figure 3. After splitting, the rays of field 1 and field 2 are respectively reflected upward and downward by the field splitting prism, enter the subsequent optical system, pass through the interferometer and Fourier transform lens, and reach the two detectors.

Figure 4 shows an embodiment of the present invention, that is, field-of-view segmentation interference imaging spectroscopy technology can be used to extend the spectrum range, that is, the systems of field-of-view and field-of-view are used for different spectral ranges, for example, field-of-view is used for In the visible and near-infrared spectrum, the second field of view is used in the short-wave infrared spectrum. It can also be used for dual optical path detection in the same spectrum to improve the signal-to-noise ratio of the system.

Example 2: The second application of the present invention is the seamless splicing technology of the field of view without loss of light energy. Restricted by the area array size of the detector device, large and wide interference imaging spectroscopy instruments need to splice the field of view. Due to the existence of the mechanical frame of the detector, it cannot be seamlessly spliced directly. However, the image plane splicing method using prism splitting will make the light energy Divide into two to reduce the signal-to-noise ratio of the interference imaging spectroscopy instrument. Using field-of-view segmentation interference imaging spectroscopy technology, the field of view is divided into two along the spectral direction by a field-of-view splitting prism and then led to the subsequent system. The left side of half of the field of view is used for detector 1, and the right side side for detector two, as shown in Figure 5. The advantage of this field-of-view segmentation interference imaging spectroscopy technology is to realize the seamless field of view splicing without energy loss of the interference imaging spectroscopy technology.

Claims (2)

1. a visual field segmentation inteference imaging spectrometer, comprise telephotolens, visual field segmentation prism, interferometer one, interferometer two, collimation lens one, collimation lens two, Fourier transform lens one and Fourier transform lens two, it is characterized in that: visual field segmentation prism is wedge angle reflecting prism, it is arranged at the image planes place of telephotolens, and the summit of visual field segmentation prism is positioned at the optical axis place of telephotolens; Two reflective surface splitting prism by visual field from the light of telephotolens are two-way reflection ray, enter interferometer one and interferometer two respectively by collimation lens one and collimation lens two; Fourier transform lens one and Fourier transform lens two are arranged in the light path of the emergent light of interferometer one and interferometer two.

2. a formation method for segmentation inteference imaging spectrometer in visual field according to claim 1, is characterized in that: comprise the following steps:

1) telephotolens converts the light from target to converging ray, images in the image planes place of telephotolens;

2) converging ray of telephotolens is reflected into two misconvergence of beams light one on the other by two reflectings surface by the visual field segmentation prism being positioned at telephotolens image planes place along spectrum direction;

3) collimation lens one and collimation lens two convert two misconvergence of beams light to two parallel ray beams respectively, and then two parallel ray beams enter interferometer one and interferometer two respectively;

4) emergent ray of interferometer one and interferometer two is received by respective detector respectively by Fourier transform lens one and Fourier transform lens two.