FBH650-40 In Stock

The FBH650-40 by ThorLabs is a high-performance bandpass filter designed to enhance the isolation of key laser lines. With its exceptional suppression in the blocking region (ODavg ≥ 4) and ≥85% transmission at the design wavelength, the FBH650-40 is perfect for use in applications that require precise filtering of Yb:YAG, Nd:YLF, Nd:YAG, HeNe, Ar, and diode laser lines.

Measuring Ø25 mm in outer diameter and 3.5 mm thick, the FBH650-40 can be used as a drop-in replacement for a fluorescence emission filter, making it an incredibly versatile choice. The filter's passband of 40 nm full width half max (FWHM) is complemented by steep cut-on and cut-off slopes, while its center wavelength of 650 nm is specified for light normally incident on the surface.

Featuring a hard-coated dielectric coating on a UV fused silica substrate, the FBH650-40 is constructed using a modified quarter-wave stack to isolate spectral bands. The coating is denser than standard bandpass filters, allowing for a single substrate to be used, which yields a more stable, longer-lasting filter. Additionally, the coating can withstand normal cleaning and handling, making this filter a reliable choice for high-quality optical components.

The housing of the FBH650-40 consists of a black anodized aluminum ring that has an arrow labeled that indicates the direction of propagation design. The ring not only makes handling easier but also enhances blocking OD by limiting scattering. The filter can be mounted into a wide variety of filter mounts and wheels, but it's important to note that retaining rings will be required to mount the filter in compatible lens tubes that are threaded internally. Removing the filter from its mount is not recommended as it poses a high risk of damaging the surface of the filter.