Abstract
A semiconductor Saturable Bragg Reflector (SBR) is a mirror structure comprising alternating layers of high and low refractive index materials with an incorporated saturable absorber. SBRs can be used to initiate and sustain ultra-short pulses in various laser systems. In order to form ultra-short pulses, SBRs with high reflectivity over a broad wavelength range are required. Furthermore, large-area SBRs facilitate easy integration in a laser cavity. One of the key elements for the realization of broad band SBRs is the development of the thermal oxidation process that creates buried low-index AlxOy layers over large areas. The design, fabrication, characterization, and implementation of broad band, high index contrast III-V/AlxOy SBRs in the form of circular mesas, as well as inverted mesa structures, is presented.
Highlights
The thermal oxidation of AlxGa1ÀxAs with high Al content (x > 0.85)1 is an enabling technology in the fabrication of optoelectronic, electronic, and photonic devices such as edge-emitting lasers,2 vertical cavity surface emitting lasers (VCSELs),3 metal semiconductor field effect transistors (MESFETs) that are based on GaAs,4 as well as III/V-oxide broad band Saturable Bragg Reflectors (SBRs)
This paper focuses on the development of large-area SBRs, which use high index contrast (Dn $ 1.8) Bragg mirrors to achieve high reflectivity over a broad wavelength range for the realization of a laser that is widely tunable and that is capable of femtosecond pulses
A semiconductor-based SBR consists of a saturable absorber that is integrated on a Distributed Bragg Reflector (DBR), which is formed by growing multiple layers of alternating indices of refraction such that each layer boundary causes a partial reflection of the incident optical wave
Summary
The thermal oxidation of AlxGa1ÀxAs with high Al content (x > 0.85) is an enabling technology in the fabrication of optoelectronic, electronic, and photonic devices such as edge-emitting lasers, vertical cavity surface emitting lasers (VCSELs), metal semiconductor field effect transistors (MESFETs) that are based on GaAs, as well as III/V-oxide broad band Saturable Bragg Reflectors (SBRs). The low refractive index of AlxOy, the stable oxide that is created by thermal oxidation, makes AlxOy extremely useful in applications where a high index contrast is required. The wet thermal oxidation of the large-area SBRs extends over hundreds of microns. At the core of broad band SBRs is the stable conversion of AlAs to lower index AlxOy via lateral wet oxidation.. In order to ensure process controllability, a physical model for the oxidation of SBRs has been developed. The first Inverted Mesa SBR (IMSBR) that is centered at 1550 nm has been
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
