FB1600-12 In Stock

The ThorLabs FB1600-12 is a high-quality soft-coated bandpass filter designed to provide users with a simple way to transmit a wavelength band of light that is well-defined while simultaneously rejecting other undesirable radiation. With a center wavelength of 1600 and an outer diameter of Ø1", the FB1600-12 features a maximum edge thickness of 6.3 mm, making it an ideal choice for a variety of applications.

The FB1600-12's design consists of a Fabry-Perot Interferometer with thin film, created through vacuum deposition techniques. This design incorporates two reflecting stacks that are separated by an even-order spacer layer. These reflecting stacks are made from alternating layers of low and high refractive index materials, resulting in a reflectance that can exceed 99.99%. By varying the number of reflecting layers and/or the thickness of the spacer layer, users can adjust the bandwidth and central wavelength of the filter to meet their specific requirements. It should be noted that due to its design, the FB1600-12 is best suited for use at a 0° angle of incidence (AOI). While it is possible to use this bandpass filter with other AOIs, doing so will cause the transmission band to shift in wavelength and may reduce its overall transmission efficiency.

To enhance handling and blocking OD, the FB1600-12 is housed in a black ring that is composed of anodized aluminum. The ring has an arrow that indicates the design propagation direction and can be mounted in a variety of compatible filter mounts and wheels. While this mounted filter is not threaded, retaining rings are required to mount it in an internally-threaded lens tube. It is not recommended to remove the filter from the mount, as the filter consists of several layers of glass held together with epoxy and the mounting ring. The glass layers form a protective barrier around the dielectric coatings, shielding them from any exposure to the environment which would otherwise cause a decrease in filter transmission efficiency.

The FB1600-12 boasts a high level of transmission in the bandpass region, but the spectral range of blocked light on either side of the bandpass region is narrow. To compensate for this, a metal-dielectric or all dielectric additional blocking component can be added. While any unwanted out-of-band radiation is eliminated with this additional blocking component, it may also reduce the filter's overall transmission throughput. Finally, it's essential to note that due to the gradual breakdown of the dielectric coatings due to water vapor, the FB1600-12 has a typical lifetime of two years. Older filters will experience a decrease in overall transmission in the passband, making it necessary to replace them periodically.