US Patent 7204611 Lamp with coating reflecting middle infrared and transmitting near infrared

A lamp for night sight applications includes a bulb that transmits both visible and infrared light. The lamp also includes a coating that reflects middle infrared radiation and is transparent to near infrared radiation to increase output efficiency in the near infrared spectral range. There may be a second coating that blocks visible light on part of the lamp—and the second coating may be on an external bulb, while the first coating is on an internal bulb. The lamp is preferably used as a vehicle headlamp with a reflector that reflects near infrared radiation and is transparent to visible light. The second coating and reflector may be on the lower part of the lamp.