中心波长14.95μm超窄带滤光片的研制

Fabrication of a Narrow Bandpass Optical Filter with Central Wavelength at 14.95μm

讨论了大气探测红外分光辐射计第1光谱通道超窄带滤光片的研制情况。采用富碲碲化铅材料作为高折射率膜层材料,通过控制沉积速率、沉积温度、真空度等工艺参数,镀制的膜层具有小的自由载流子浓度,整个膜系具有低的光吸收和高的透射能量。研制出入射光束半锥角Φ为18°时,中心波长14.95μm、带宽0.065μm、相对带宽小于0.5%的长波CO2超窄带滤光片。该超窄带滤光片已实现空间应用5年,在天气预报数据获取中工作稳定。

The design and fabrication of infrared ultra-narrow bandpass filters is presented, which have been employed in the channel No. 1 in the infrared atmospheric sounder （IRAS）. The filters are fabricated using Te-rich PbTe as the high-index coating material. By choosing suitable deposition rate and substrate temperature, the carrier concentration in the layers of PbTe can be controlled to a lower level in order to obtain the higher transmittance for the filters. The filters have a central wavelength at 14.95 μm and a bandwidth of 0. 065μm. The relative bandwidth is less than 0.5%. The filter has been used in space and worked stably for five years in the data acquisition of weather forecast.