多波段紅外線酒精偵測系統

Abstract

在此論文中，整合了本實驗室在紅外光元件製程上既有的研究成果，包括針對酒精氣體的三波長窄頻紅外線發射器，以及相對應波長的窄頻偵測器，實現多波段的酒精氣體偵測系統。發射器部分採用金屬柵欄嵌入波導型紅外線發射器的結構，並且在上層堆疊 金/二氧化鈦/金 三層島狀結構以產生侷域型的表面電漿子模態的發射。偵測器部分採用 金/氫化非晶矽/金 的結構，藉由探討氫化非晶矽厚度以及上層金屬柵欄線寬，與波長紅位移的關係來微調所要的偵測波段以及製作不同的窄頻紅外線偵測器。我們設計一個非色散式紅外線分析系統來量測不同酒精氣體濃度，並且嘗試將此系統微型化，與電訊號分析系統整合成一個手持式氣體偵測裝置，包含發射器腔體、氣體腔體、偵測器的載具、上述的窄頻紅外線發射器與偵測器、訊號放大器、類比數位轉換器以及顯示器模組。

The thesis investigated the integrated infrared device process, including triple-wavelength infrared thermal emitter and the corresponding plasmonic infrared photodetector developed in our laboratory to realize a multi-band alcohol detection system. The emitter adopt the structure of waveduide mode emitter embedded with golden grating in the dielectric layer and adding the Au / TiO2 / Au island structure on the top to produce the emission of localized surface plasmon resonance. The detector is Au/a-Si:H /Au grating structure which can be investigated by observing the wavelength red-shift wih the change of dielectric thickness and metallic linewidth. These devices are applied in non-dispersive infrared (NDIR) system for alcohol detection. In addition, we have tried to miniaturize this system and integrate it with the electric signal system to make a portable apparatus, including the emitter, photodetector, emitter chamber, gas chamber, detector holder, signal amplifier, ADC and display module.