What does Alluxa do?
About us. Why Alluxa – Alluxa is an ISO 9001:2015 certified, ITAR registered manufacturer of high-performance optical filters and thin-film coatings. Alluxa has rapidly grown from a small startup to a world leader in precision thin films.
How do optical filters work?
Optical filters selectively transmit light in a particular range of wavelengths, that is, colours, while absorbing the remainder. They can usually pass long wavelengths only (longpass), short wavelengths only (shortpass), or a band of wavelengths, blocking both longer and shorter wavelengths (bandpass).
What are Longpass filters?
Longpass filters are optical filters that reflect short wavelengths while transmitting, or passing, long wavelengths. Conversely, Shortpass filters transmit short wavelengths but reflect long ones.
What are optical filters made of?
There are two general categories of optical filters: absorptive and dichroic (also called interference) filters. Absorptive filters tend to be made from glass with selected organic or inorganic compounds added.
What is edge filter?
Edge filters separate a broad spectrum of light into two components: a transmitted and a blocked component. These filters are defined by either a cut-on or a cut-off slope, which provides the transition between a high blocking region and a high transmission region.
What is a short pass filter?
A shortpass filter or short wavepass filter (SP filter) is a filter that transmits at shorter wavelengths and rejects longer wavelengths. By design, the transition in a shortpass filter between the 50% cut-off or cut-on to rejection is quite sharp.
What are the optical properties of thin film?
4.2. 3 Optical properties. The investigation of optical properties of thin films include very well developed methods like reflectivity (R) and transmission (T) measurement. Simple optics (Fresnel’s law) teaches that the reflectivity of a thin-film coated surface depends on the wavelength of the impinging photons.
What is a cut on wavelength?
Cut-on wavelength describes an optical filter edge transition where transmission increases sharply over an increasing wavelength range, such as seen with a longpass filter. Conversely, cut-off wavelength describes an edge transition that decreases over a wavelength range, as seen with a shortpass filter.
What is OD filter?
Neutral Density (ND) filters are designed to reduce transmission evenly across a portion of a specific spectrum. ND filters are typically defined by their Optical Density (OD) which describes the amount of energy blocked by the filter.