The 157 nm filter is a deep ultraviolet (DUV) ultra-narrow band interference filter with a center wavelength of 157 nm ±1 nm, a full width at half maximum (FWHM) ≤10 nm, a peak transmittance ≥15%, and an OD6@157±15 nm. It is specifically designed for F2 excimer laser (157.6 nm) systems. The substrate is made of high-purity CaF? or MgF? single crystal, coated with a low-loss LaF?/MgF? multilayer dielectric film, with a surface roughness <0.5 nm RMS, capable of withstanding >1 J/cm2 pulsed laser irradiation. Packaged in a Class 1000 cleanroom, it is suitable for high-end applications such as 157 nm lithography, wafer defect detection, spectral metrology, and deep ultraviolet Raman spectroscopy.