Microscopic hyperspectral cameraA technological balance needs to be achieved between spatial resolution (object detail capture capability) and spectral resolution (spectral detail resolution capability), with the core logic being the collaborative optimization of optical design, spectral technology, and hardware configuration to meet the needs of "spatial spectral" joint analysis at the microscale. The following analysis will be conducted from three aspects: technical principles, balancing strategies, and application scenarios:

1、 Technical principle: Contradiction between spatial and spectral resolution

1. Spatial resolution

The minimum distance at which a camera can distinguish adjacent objects on the imaging plane is usually determined by the numerical aperture (NA), pixel size, and optical system aberration correction capability of the microscope objective. For example, under a 40x objective lens, the spatial resolution can reach 1.125 μ m, which means that micrometer level object details can be distinguished.

2. Spectral resolution

pointMicroscopic hyperspectral cameraThe ability to distinguish the minimum spectral interval is determined by the slit width, grating line density, and detector performance of the spectral element (such as prism grating combination). For example, a spectral resolution of 2.8nm means that spectral peaks with a wavelength difference of only 2.8nm can be distinguished.

3. Root cause of contradiction

-Competition for optical resources: Improving spectral resolution requires increasing the size or complexity of spectral elements (such as reducing slit width), but it will disperse the incident light energy and reduce spatial resolution; On the contrary, optimizing spatial resolution requires more precise optical focusing, which may compress the spectral analysis space.

-Detector pixel allocation: The total number of detector pixels is fixed. If more pixels are allocated for spectral dimension (such as push scan imaging), the spatial dimension pixels will decrease, resulting in a decrease in spatial resolution.

2、 Balancing Strategy: Technical Collaboration and Parameter Optimization

1. Selection of Spectral Technology

-Prism grating combination: By pre dispersing light through a prism and then splitting it through a grating, it can balance a wide spectral range (such as 400-1000nm) with higher spectral resolution (such as 2.8nm), while maintaining spatial resolution through the high NA value of the microscope objective.

-Liquid Crystal Tunable Filter (LCTF): Tunes the wavelength electronically without mechanical scanning, simplifies the system structure, but has lower spectral resolution (such as 8nm), making it suitable for scenarios that require higher speed than accuracy.

2. Collaborative design of detectors and optical systems

-High pixel array CCD/SCMS: such as 2048 × 2048 pixel detector, can allocate more pixels for spatial dimension, improve spatial resolution (such as 1.125 μ m), while maintaining spectral resolution through slit optimization.

-InGaAs detector: suitable for the near-infrared band (900-1700nm), it has high sensitivity and low noise characteristics, and can maintain spectral resolution (such as 6nm) under low light conditions, while improving spatial resolution through small pixel sizes (such as 30 μ m).

3. Innovation in scanning mechanism

-Push scan imaging: Two dimensional imaging is achieved through micro scale translation of the stage, avoiding distortion introduced by mechanical scanning. At the same time, high-precision stepper motors are used to control the scanning speed, balancing space and spectral sampling rate.

-Snapshot imaging: adopting multi-channel spectral design, obtaining spatial spectral data cube at once, eliminating the influence of scanning time on resolution, but requiring higher cost optical components.

3、 Application scenario: Demand driven balanced selection

1. Biomedical Sciences

-Requirement: High spatial resolution (such as 1 μ m) is required to observe cell structure, while high spectral resolution (such as 5nm) is needed to distinguish tissue components.

-Solution: Adopting a 40x objective lens and prism grating spectroscopic system, with a spectral range of 400-1000nm, spatial resolution of 1.125 μ m, and spectral resolution of 2.8nm, suitable for pathological section analysis.

2. Materials Science

-Requirement:Microscopic hyperspectral cameraWide spectral range (such as 900-1700nm) is required to detect the infrared characteristics of materials, while medium spatial resolution (such as 5 μ m) is needed to observe microscopic defects.

-Solution: Using InGaAs detector and transmission grating for spectral resolution of 6nm and spatial resolution of 320 × 320 pixels, suitable for semiconductor wafer inspection.

3. Environmental monitoring

-Requirement: Quickly obtain large-scale data with low spatial resolution requirements (such as 10 μ m), but high spectral resolution (such as 3nm) is needed to distinguish pollutants.

-Solution: Adopting LCTF spectroscopy and low pixel detector, with a spectral range of 400-720nm and a spectral resolution of 8nm, suitable for water quality spectral analysis.