Patent ID: 8300313
Filing Date: 2012-10-30
Classification: G01J,G01N,G02B

Abstract:
1. A method of making an optical bandpass filter for transmitting a band of ultraviolet light within the range of 230 nanometers to 320 nanometers and with extended out-of-band blocking comprising the steps of: providing a substrate having front-side and backside surfaces; forming a transmission filter on at least one of said surfaces, said transmission filter consisting of alternating layers of at least two hard coating materials of a higher refractive index and a lower refractive index respectively; wherein each individual layer of the alternating layers is deposited by a data processor controlled process comprising the steps of: calculating with the data processor, a theoretical transmission (T calculating with the data processor an expected deposition time (t measuring, during the deposition of the individual layer for a period of time less than (t determining with the data processor when deposition of the individual layer is to terminate based upon the theoretical transmission (T wherein the calculation of (t where T is a level of a monitoring signal within the individual layer, where n where H is defined as where Re(pq*) is a real part of a product of a complex number p and a complex conjugate of a complex number q, defined as where θ where D is an in-situ fitted parameter which models a decrease in transmission due to extinction in the UV spectrum for any previously-deposited layers on the front-side and backside surfaces and in the substrate, where T where R where A where α is the substrate single-pass absorption value, and where A