Delta Optical Thin Film: Continuously Variable Bandpass Filters for Hyperspectral Imaging
Hyperspectral imaging (HSI) has been used for a couple of decades in applications such as satellite imaging, air reconnaissance and other not overly price sensitive markets. Classical Hyperspectral imaging cameras use prisms or grating as dispersive elements. These cameras are bulky, sensitive to misalignment and very expensive. The advent of alternative approaches makes HSI attractive for volume markets or even consumer products, for example cancer detection, precision farming, food testing in supermarkets and many more.
Delta Optical Thin Film A/S develops and manufactures custom Linear Variable Bandpass Filters (LVBPF) for mid-size and full-frame CCD/CMOS sensors (e.g. 25mm x 25mm or 24mm x 36mm). These filters offer very high transmission and are fully blocked in the light sensitive wavelength range of silicon-based detectors (200nm to 1150nm). The combination of LVBPFs with silicon detectors allows the design of very compact, robust and affordable HSI detectors that offer several advantages and benefits over conventional approaches:
- Huge aperture compared to grating and prism
- Higher transmission than grating and prism
- Short measurement time
- High suppression of stray light
- Excellent signal to noise ratio
Delta Optical Thin Film A/S welcomes requests for custom designed Linear Variable Bandpass Filters. Available for immediate testing are filters with the following specifications:
- Centre wavelength range 450nm to 880nm, bandwidth approximately 2% of centre wavelength, transmission 60% to 90%, blocking range 200 nm to 1150nm, blocking level OD4, size 24mm x 36mm
- Centre wavelength range 450nm to 850nm, bandwidth approximately 4% of centre wavelength, transmission 70% to 90%, blocking range 200nm to 1100nm, blocking level OD4, size 25mm x 25mm
- Centre wavelength range 800nm to 1000nm, bandwidth approximately 0.6% of centre wavelength, transmission >70%, blocking range 200nm to 1200nm, blocking level OD4, size 19mm x 8mm
- Centre wavelength range 800nm to 1000nm, bandwidth approximately 1% of centre wavelength, transmission >70%, blocking range 200nm to 1200nm, blocking level OD4, size 19mm x 8mm
The sizes are given as height x length, where height is perpendicular to the wavelength gradient and length is along the wavelength gradient. The filters can be diced to smaller sizes.
About Delta Optical Thin Film A/S
Delta Optical Thin Film A/S (www.deltaopticalthinfilm.com) is the leading supplier of advanced, high performance linear variable filters commonly used in a variety of biomedical imaging applications including fluorescence microscopy, flow cytometry, monochromators and micro-plate readers among others.
Delta Optical Thin Film A/S also provides single, multiband, laserline and broadband band pass filters; long pass filters; short pass filters; notch filters; dichroic and polarizing beam splitters along with other custom coated optical components.
Delta Optical Thin Film A/S offers a wide range of high efficiency durable ultra-hard coated filters that have set the standard for high performance and precise operation. With its unique design tools and decades of experience, Delta is able to provide highly competitive standard filters and customized filters and optical components tailored to customers’ specific applications.