Snapshot hyperspectral imaging captures a full hyperspectral cube in a single shot. This method is fast and effective for dynamic scenes. It allows scientists and engineers to spectrally inspect samples by rapidly acquiring selected spectral and spatial data from a field of view at video rates.
In imec’s patented technology a Fabry–Pérot etalon (a pair of parallel semi-transparent reflecting surfaces) is deposited on each pixel of an image sensor. This effectively places a band-pass spectral filter on each pixel of an image sensor array. The etalon distance is carefully controlled and this makes it possible to limit the sensitivity of each pixel to a particular spectral band. When pixel-sized etalons are fabricated directly on the pixel-structure instead of on a glass window, issues such as cross-talk between pixels are minimized.
For image sensors that are used in imec’s Snapshot cameras, pixel-level bandpass filters are deposited in a 3×3, 4×4 or 5×5 mosaic pattern. The operating principle is conceptually similar to that of the familiar RGB Bayer pattern, except that instead of the familiar repeating pattern of Red-Green, Green-Blue quads the repeating pattern could be (for example) a 4 x 4 pattern with 16 different bandpass filters. Instead of the familiar RGB image that results from a Bayer color-filter pattern, an single snapshot captures data that can be parsed into 16 different sub-images each of which captures spatial information that is specific to a particular wavelength.
Snapshot cameras generate spectral and spatial data at video rates, capturing the image circle that is projected by the lens or microscope optics onto the focal plane. Pixel values are read out and can now be rearranged with each λ plane along the z-axis representing the spatially sampled (x,y) intensity values measured for a particular wavelength.
Snapshot cameras are ideal for applications requiring high-speed imaging, like conveyor belt sorting or real-time monitoring.
Snapshot selection table
Click on a green button within the above table to get more details about a particular camera model.
