Laser protective device with reflecting filter on non-absorbing and absorbing substrates

摘要

A laser reflecting has a low transmittance at one or more laser wavelengths while substantially transmitting all other wavelengths in the spectral range of interest, is coated on one or both sides of an absorbing or non-absorbing substrate. A laser reflecting filter on both sides of an absorbing substrate can result in an enhancement of the absorption of laser light by multiple reflections of the laser light in the absorbing substrate. The high transmittance of the laser-reflecting filter at non-laser wavelengths results in a relatively high overall transmittance through the coated substrate. In the specific case of laser reflecting coatings on a lens to protect an eye, this allows a high luminous transmittance and good color discrimination.

主权项

1. A laser protective device in the form of an article selected from the group consisting of: eyeglasses, an eyeshade and a lens adapted to be placed over a surveillance camera, comprising:
a transparent substrate; and a multi-layer laser reflecting filter based on optical interference deposited on a rear or both sides of the transparent substrate configured to substantially reflect at least two laser wavelengths while substantially transmitting non-laser wavelengths in a given spectral range, and wherein the multi-layer laser reflecting filter is deposited directly on said rear or both sides of the substrate, the multi-layer laser reflecting filter(s) substantially reflects laser light in wavelength bands centered at or around at least two of the following laser wavelengths; 405 nm, 445 nm, 532 nm, 635 nm, 650 nm, 808 nm and 1064 nm, said wavelength bands encompassing spectral shift occurring between 0° and 30° angles of incidence, and transmits a major portion of the wavelengths outside the wavelength bands, and wherein when said protective device is in the form of eyeglasses or any eyeshade, said given range is from 380 nm to 780 nm and when said protective device is in the form of a lens adapted to be placed over a surveillance camera, said given range is from 200 nm to 1200 nm, and wherein the multi-layer laser reflecting filter deposited on the rear side of the transparent substrate incorporates as one of the layers thereof at least one absorbing layer to reduce ambient light directly reflected off the rear side of the transparent substrate.