초록 ▼

A miniaturized NDIR gas sensor is manufactured using semiconductor micromachining techniques from a semiconductor material such as Si or GaAs. The NDIR gas sensor comprises an optical waveguide, a light source at one end of the waveguide, at least one light detector at the end of the waveguide oppos

A miniaturized NDIR gas sensor is manufactured using semiconductor micromachining techniques from a semiconductor material such as Si or GaAs. The NDIR gas sensor comprises an optical waveguide, a light source at one end of the waveguide, at least one light detector at the end of the waveguide opposite the light source, a diffusion type gas sample chamber formed within the waveguide and interposed in the optical path between the light source and light detector so that the light source and light detector are thermally isolated from the gas sample, and a separate bandpass filter interposed between the light source and each light detector. A miniaturized NDIR gas sensor is also provided in which the light source and light detector are located on the same end of the optical waveguide is also provided. Because the NDIR sensor is fabricated out of a semiconductor material, the source driver and signal processing electronics may be added directly to the sensor using integrated circuit fabrication techniques. Particles and smoke and dust may be kept out of the sample chamber by application of a gas permeable membrane over apertures in the sample chamber walls.

대표청구항 ▼

[ I claim:] [1.] An improved NDIR gas sensor, comprising:a. a first semiconductor material substrate;b. a second semiconductor material substrate attached to the first substrate;c. an optical waveguide formed from the first and second substrates;d. a light source integrally formed on one of the subs

[ I claim:] [1.] An improved NDIR gas sensor, comprising:a. a first semiconductor material substrate;b. a second semiconductor material substrate attached to the first substrate;c. an optical waveguide formed from the first and second substrates;d. a light source integrally formed on one of the substrates and positioned at one end of the optical waveguide;e. a light detector integrally formed on one of the substrates and positioned at the end of the optical waveguide opposite the light source;f. a bandpass filter interposed in the optical path between the light source and light detector;g. a pair of semiconductor material windows interposed in the optical path between the light source and light detector so as to define therebetween a sample chamber within the waveguide and thermally isolate the light source and light detector, wherein the sample chamber extends along an indirect path; andh. means for permitting diffusion of gas into and out of the sample chamber.