New NRL glasses for multispectral imagers in visible to LWIR (Conference Presentation)

NRL is developing new glasses that transmit within the visible to LWIR range for use in multispectral imaging. We had previously developed NRL glasses which transmit in 0.9 to > 12 µm in wavelength, with refractive index ranging from 2.38 to 3.17, to expand the glass map and provide compact solutions to multispectral imaging systems. These glasses were specifically designed to have comparable glass molding temperatures and thermal properties so that they can be laminated and co-molded into optics with reduced number of air-glass interfaces (lower Fresnel reflection losses). These NRL glasses also have negative or very low dn/dT, making it easier to athermalize the optical system. A set of NRL glasses can be diffused to make infrared graded index (IR-GRIN) optics. Our multispectral optics designs using these new materials demonstrate reduced size, complexity and improved performance. The glass database compatible with Zemax and CodeV is available for distribution. We are adding n