Waveguides for nitride based quantum cascade lasers

• Waveguide designs for AlGaN-based near-infrared quantum cascade lasers are investigated using a finite-difference method mode solver. Because of the negligibly small refractive index difference between the AlN/GaN/AlGaN gain region and the surrounding AlGaN current injection and extraction layers, a low refractive index substrate (sapphire) and a low refractive index dielectric (SiO2) are used for vertical confinement of the optical field. A ridge waveguide with an off-center contact metallization is used for lateral confinement. The off-center contact allows for the propagation of a TM mode with low metal induced loss and sufficient optical confinement in the gain region. A viable waveguide design with a metal-induced loss of 6.1 cm-1 and a confinement factor of 0.52 is demonstrated.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Telekommunikation (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Telecommunications (hsv//eng)

Keyword

waveguide

near infrared

quantum cascade laser

nitrides

Publication and Content Type

art (subject category)

ref (subject category)