FESH1000 In Stock

The FESH1000 by ThorLabs is a high-performance shortpass filter designed to isolate specific regions of a spectrum with exceptional precision and durability. The FESH1000 provides better transmission, steeper slopes, greater blocking, and increased durability when compared to its soft-coated counterparts. This filter is ideal for use as raman spectroscopy filters or emission filters for fluorescence applications.

The FESH1000 filter boasts superior transmission, steeper slopes, and greater blocking compared to its soft-coated counterparts. With an optical density (OD) of over 5 in the rejection region and over 90% transmission in the transmission region, this filter delivers unparalleled performance. Crafted with a UV fused silica substrate that boasts a hard-coated and durable dielectric coating, the FESH1000 features a modified quarter-wave stack construction that uses interference effects to isolate spectral bands. These coatings are denser than standard filters, resulting in a more stable, longer-lasting filter that can withstand normal amounts of necessary handling and cleaning when working with high-quality optical components.

The housing of the FESH1000 filter is a anodized black aluminum ring that has an arrow that indicates the direction of design propagation. This ring not only makes handling easier but also limits scattering which boosts the blocking OD. It can be mounted in a variety of filter mounts and wheels, but it is important to note that Ø1" retaining rings are required to mount the filter into an internally-threaded SM1 lens tube. It should be noted that it is not recommended to remove the filter from its mount due to the heightened risk of the filter sustaining damage. Additionally, the FESH1000 has an outer diameter of 25.0 mm and a clear aperture of Ø21.1 mm.