461+689nm, 1/4λ, dia12.7mm, Dual Wavelength Waveplate（QWPZ461+689）

This 461+689 nm dual-wavelength quarter-wave plate is designed to introduce quarter-wave retardance at both 461 nm and 689 nm design wavelengths. It is suitable for laser systems, quantum optics, and optical measurement setups using 461 nm and 689 nm laser sources. It helps control polarization state at two distinct wavelengths simultaneously to support polarization-sensitive measurement and complex laser alignment. Key specifications: Wavelength / main spec: 461 nm and 689 nm design wavelengths Bandwidth / transition spec: Quarter-wave (1/4λ) retardance at the design wavelengths Transmission / blocking: See specification table for coating and transmission details Format / custom option: 12.7 mm diameter (unmounted or mounted); custom formats available on request