利用光子晶體奈米結構製作高效率光子晶體面射型雷射

Abstract

本計畫主要目的在利用AlGaAs、以及AlGaInP這二種材料以奈米製程的方式製作紅外光(780nm~980nm)以及紅光（635nm~650nm）光子晶體面射型雷射。一般來說，雷射的應用常被兩種操作特性所限制，第一是雷射的發散角，雷射發散角的大小將會影響後端應用的耦合以及所需要的雷射特性而影響整體雷射元件的製作成本；其次為半導體雷射高功率輸出的困難性。因此，我們利用光子晶體面射型雷射的優點，如具有較好的光限層導致較小的發散角(小於6度以下)以及大面積且高功率雷射出射等特性，將光子晶體製作於AlGaAs以及AlGaInP這二種材料中，並且搭配低折射率層的設計，將光場有效的侷限於光子晶體以及多重量子井中，達到較高的光侷限因子(confinement factor, Γ)，最後達到低操作電流密度且高發光功率的光子晶體面射型雷射元件。而AlGaInP這種材料，可以應用於高解析度的雷射印表機、高密度的光儲存以及雷射投影機等應用中，藉此增加解析度以及儲存容量的大小；而AlGaAs此材料可以作為光激發範圍為780nm~980nm雷射光源，可提升台灣雷射產業的競爭力。

The project is focused on the fabrication of high power photonic crystal surface emitting laser ranging from 780 nm to 980 nm, and from 635 nm to 650 nm by using AlGaAs and AlGaInP materials. In general, the applications of diode lasers will be limited by two characteristics: the first one is the divergence angle of the diode laser. The spot size and divergence angle of the diode laser will play important roles both in the assembly difficulty and the system properties we desired, and then increase the fabrication cost and constrain many other possible applications. The second one is the laser with high power output. According to the advantages of photonic crystal surface emitting laser including better optical confinement caused lower divergence angle of smaller than 6 degree, high output power of lasing emitting characteristics caused by large lasing area and so on, we will fabricate the photonic crystal nanostructure on AlGaAs and AlGaInP materials with low refractive index layer. The optical field will effectively be confined in the photonic crysal nanostructure and multi-quantum wells to enhance the confinement factor (Γ), obtained the lower operation current density, and high output power of photonic crystal surface emitting laser devices. The red light of AlGaInP photonic crystal surface emitting lasers can be applied into the optical storage, high resolution laser printer, high density optical storage, and projector to enhance the resolution and the storage density; the laser fabricated by AlGaAs can be an optical pumping source between 780nm and 980nm. The development shall promote the technology of semiconductor lasers in Taiwan industrial fields.