Patent ID: 11880018
Assignee: RAYTHEON COMPANY
Field: Optics (Instruments)
Classification: CPC G  B | IPC B  G

Claim 0:
1. An optical window comprising:
multiple alternating layers of different materials;
wherein an optical sensor associated with the optical window is configured to receive a light and/or signals through the optical window;
wherein the optical window, while receiving the signals, is configured to:
have some of the multiple alternating layers removed responsive to hypersonic flow past the optical window while leaving in place other of the multiple alternating layers; and
maintain anti-reflection and/or band rejecting optical characteristics over a range of wavelengths of the light as some but not all of the multiple alternating layers, including at least one of the layers of each of the different materials, are removed responsive to hypersonic flow past the optical window; and

wherein one of the different materials is a material resistant to removal and includes zirconium, yttrium, or dysprosium.