New or used optical & electronic test equipment

81001FF Fixed Filter - this is the filter holder with a mesh (looks like a fine metal screen) diffraction filter to provide approximately 10 dB of attenuation. The attenuation is quite flat across wavelength. Two can be stacked for 20 dB of attenuation. The filters do exhibit fairly high polarization dependant loss, however, on the order of 0.05 dB p-p. Adding the 81000DF (see next) before the 81001FF can decrease this considerably, probably to less than 0.02 dB p-p, while creating about 25 dB of attenuation.