A Comparative Study of Fabrication of Long Wavelength Diode Lasers Using CCl&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;F&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;/O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;/CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;

B Cakmak,T Karacali,M Biber,C Duman

doi:10.4236/opj.2013.32b005

Abstract

We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers. Gas mixtures of CCl2F2/O2 and H2/CH4 were used to form ridge-waveguide on the lasers with InP-based material structures. As known, chlorine- and hydro-carbon based gases are used to fabricate ridge-waveguide structures. Here, we show the difference between the structures obtained by using the both gas mixtures in which surface and sidewall structures as well as performance of the lasers were analysed using scanning electron microscopy. It is demonstrated that gas mixtures of CCl2F2/O2 highly deteriorated the etched structures although different flow rates, rf powers and base pressures were tried. We also show that the structures etched with H2/CH4 gas mixtures produced much better results that led to the successful fabrication of two-section devices with ridge-waveguide. The lasers fabricated using H2/CH4 were characterized using output power-current (P-I) and spectral results.

Highlights

InP-based devices have started to dominate opto-electronics because lasers and related devices with InGaAsP/InP and AlGaInAs/InP heterostructures are suitable for low-loss fibre communications and integrated optics
We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers
We show that the structures etched with H2/CH4 gas mixtures produced much better results that led to the successful fabrication of two-section devices with ridge-waveguide

Summary

Introduction

InP-based devices have started to dominate opto-electronics because lasers and related devices with InGaAsP/InP and AlGaInAs/InP heterostructures are suitable for low-loss fibre communications and integrated optics. Various dry etching techniques, such as plasma etching [1,2], reactive ion etching (RIE) [3,4,5], ion beam etching (IBE) [6,7], reactive ion beam etching (RIBE) [8,9], chemically assisted ion beam etching (CAIBE) [10,11] and inductively coupled plasma (ICP or RIE/ICP) etching [12] have been successfully used to fabricate InP-based devices to date Of these techniques, RIE and ICP, which are well known and widely used dry-etching methods, provide higher anisotropy and better surface morphology when compared with other techniques. We have fabricated two-section InGaAsP/InP and AlGaInAs/InP laser devices with ridge waveguide using chlorine- and hydrocarbon based gas mixtures and reported the results comparatively

Fabrication of the Lasers

Formation of Ridge-waveguides

Characterisation Measurement Results

Conclusions