Lens MTF

Traditional hyperspectral imaging scanners contain a lot of precision optics to select and diffract the light. This makes them relatively heavy, expensive, slow and delicate – with a need for frequent recalibration.

Selecting the required properties is a tradeoff, driven by the requirements of the application. If you know which spectral bands to look for, there’s no need to capture the full spectral range. Especially because a lower resolution will enable faster acquisition speeds and open new possibilities with hyperspectral video imaging.

调制传递函数

Our filters eliminate the complex optical camera design and can be deposited on a commercial CMOS imager, like the one in your smartphone or a model with scientific imaging capabilities.

As an example, a diffraction-limited lens with an f/# of 4 and a working wavelength of 0.55µm, the cut-off spatial frequency is approximately 454lp/mm and the MTF is approximately 0.50 at the spatial frequency of 1837 lp/mm. • Manufacturing tolerances An optical system cannot perform better than its diffraction-limited MTF. Manufacturing errors and internal-reflections of optical systems can decrease the MTF values. Typical manufacturing tolerances are listed in the following table.

mtf光学

Knowing the possible MTF curves and manufacturing tolerances can help optical designers more accurately predict the system performance and estimate fabrication costs of optical products.

Point spreadfunction

Hyperspectral imaging technology is designed to make images that reveal a maximum of spectral information for each pixel of the image.

Another way of looking at a hyperspectral image is as a set of image layers, each in another wavelength of the electromagnetic spectrum. The combination of those layers is called a hyperspectral data cube.

The Modulation Transfer Function (MTF) is an important tool to quantify the overall imaging performance of a system. MTF is a function of spatial frequency (v), which is generally in the form of line pairs per millimeter (lp/mm). Every component within the system has an associated modulation transfer function. This includes the imaging lens, sensor, electronic board, etc.

Where λ is the wavelength expressed in mm and f/# is the lens focal-ratio. An optical system cannot transmit information of spatial frequencies higher than the cutoff frequency. The diffraction-limited MTF is used to predict the upper performance limit of a lens system.

Opticaltransfer function

Imec’s hyperspectral imaging technology takes a different approach. As a world-leading R&D hub in nanotechnology, we have developed a wafer-level CMOS process to integrate thin-film spectral filters directly on the pixels of the image sensor.

Shanghai Optics has an experienced engineering team to bring customers the most feasible design at the fastest speed and most affordable cost. Shanghai Optics offers variety of services in lens design, research and production.

Our unique on-chip hyperspectral imaging technology allows us to make different spectral filter patterns. Those fall into two categories:

Edge spreadfunction

modulationtransferfunction中文

Imec can assist you in tailoring its hyperspectral imaging technology to your application. For instance, why not use one of our high-resolution cameras  to define which frequency bands are relevant for your needs? Afterwards, we can help you to build your dedicated filters or camera system.

Optical design is the process of studying application requirements and designing optical systems to meet specific needs of optical instruments. The entire system may include optics, light source, sensor, electronics boards, display device, and/or other components. The system performance is not totally dependent on the optics. Every component within the system has contributions to the overall performance of optical instruments. For creating optical specifications and designing the optical components or assemblies, designers need to have a wide knowledge of opto-electronic components such as optical receivers and light sources, know the system performance limits, in-depth understand manufacturing tolerances and fabrication costs.

Room 609, 6/F, Global Gateway Tower, No.63 Wing Hong Street, Cheung Sha Wan, Kowloon, Hong Kong +852-54993705 info@shanghai-optics.com

Read this 2023 press release about imec's combined VIS & NIR spectral camera system, complemented with hi-res RGB imaging, for data acquisition at video rate – allowing flexible assessment of the pros and cons of different spectral resolutions and ranges.

Alpha Industrial Park, Tu Thon Village, Ly Thuong Kiet Commune, Yen My District, Hung Yen Province Vietnam 17721 +84 221-730-8668 rfqvn@shanghai-optics.com

Of course, we can also develop custom hyperspectral image sensors, with your desired pattern lay-out, filter specification, imager chip, ... All the way up to the design of the complete camera system.

This website offers you an overview of our ready-to-use evaluation kits, including remote support, and the easy-to-use HSI STUDIO, HSI MOSAIC and HSI SNAPSCAN software suites to make hyperspectral imaging accessible to anyone.

There are multiple hyperspectral imaging technologies. Each applies different techniques to filter the light and capture the image data. The key differentiators you need to keep an eye on are: