摘要 |
An infrared gas detector includes an infrared reception member, a package configured to accommodate the infrared reception member, and an optical filter. The infrared reception member includes a plurality of thermal infrared detection elements each configured to detect infrared based on heat caused by received infrared. The thermal infrared detection elements are placed side by side. The package is provided with a window opening configured to allow the infrared reception member to receive infrared. The optical filter is attached to the package so as to cover the window opening, and includes a plurality of filter elements respectively corresponding to the plurality of the thermal infrared detection elements. Each of the filter elements includes a filter substrate made of an infrared transparent material, a transmission filter configured to transmit infrared of a selected wavelength, and a cut-off filter configured to absorb infrared of a wavelength longer than the selected wavelength. The transmission filter and the cut-off filter are formed over the filter substrate. The filter substrate is thermally coupled to the package. The transmission filters of the respective filter elements are configured to transmit infrared of the different selected wavelengths. |