What is Fluorescence Spectroscopy?

Fluorescence is the phenomenon where a molecule absorbs light within its absorption band and then emits this light at longer wavelengths within its emission band. This phenomenon can be used to identify, quantify, and observe chemical activity, and it is a popular method due to its high levels of sensitivity, simplicity, and specificity. Fluorescence spectroscopy […]

Linear Variable Filter or Continuously Variable Filter?

Over the past six years, Delta Optical Thin Film A/S have been producing and further developing spatially variable filters. These types of filters have spectral characteristics that change spatially and were around for several years before we started to develop our own. Traditionally, when people use the term linear variable filter they mean a filter […]

Delta Optical Thin Film Linear Variable Filter Used in new Laser Attenuator

A new Laser Attenuator has been developed, which utilizes an ultra-hard coated, Laser Optical Multilayer Attenuator (LOMA) filter from Delta Optical Thin Film. The laser attenuator enables computer-controlled attenuation of a monochromatic light source from 1% – 99% within the wavelength region of ~ 550 nm – 1000 nm. It provides the user with safe, […]

Bifrost Continuously Variable Bandpass Filters for Image Sensors

Charged-couple device (CCD) and complementary metal oxide semiconductor (CMOS) sensors are the most common types of image sensors. They work by converting incident radiation into electrical signals that produce the image. In order for these sensors to work successfully, they require a bandpass filter, which is the element that determines which wavelengths are allowed to […]

What is a Beamsplitter?

A beamsplitter is an optical element that is used to split incident light into two or more beams by wavelength, polarization or intensity. Standard models are often used with unpolarized light sources in applications where the state of polarization isn’t important. These beamsplitters are designed to split unpolarized light at a specific reflection/transmission ratio. Other […]

The Story Behind the Bifrost Continuously Variable Bandpass Filters Name

In 2015 we launched our range of continuously variable bandpass filters that are specifically designed for hyperspectral imaging, and with this launch, we invited our customers to help name them. The response we had was immense, with a number of fantastic suggestions including ‘Rainbow’ and ‘Mantis’. The winning suggestion was ‘Bifrost’ from Martin H. Skjelvareid. […]

Hyperspectral Imaging for Cancer Detection

Hyperspectral imaging is used to collect and process images across the electromagnetic spectrum. The technique is a combination of spectroscopy and 2D or 3D imaging, and it is used to obtain the spectrum for each pixel in the image. Obtaining the spectrum enables hyperspectral imaging to be used for detecting processes, identifying materials, and finding […]

Ultra-Hard-Coated Optical Filters

Optical thin film filters are devices that are used to selectively transmit, or reflect different parts of the electromagnetic spectrum, and they are used for a range of different applications. Standard optical filters include longwave and shortwave pass filters, bandpass filters, and dichroic and polarization beamsplitters. What is an Optical Filter Coating? Optical thin film […]

Optical Bandpass Filters from Delta Optical Thin Film

An optical bandpass filter is an element that allows wavelengths within a certain range to pass through and blocks any wavelengths outside of that range. These filters are often used for fluorescence microscopy, imaging, and spectroscopy among other applications. The passband is the range of the spectrum that is allowed to pass through the bandpass […]