Near-infrared single photon sources employing site-selected InAs/InP quantum dot microcavities

摘要

We discuss the design, fabrication and characterisation of optical microcavities suitable for application with single, site-selected InAs/InP quantum dots emitting around λ = 1550 nm. The fabrication procedures that we employ allow high finesse cavities to be constructed around single quantum dots with a known nucleation site and ground state emission energy. Two types of cavity are explored: (ⅰ) pillar cavities in which the quantum dot can be located within the semiconductor spacer layer between two dielectric Bragg reflectors and (ⅱ) photonic bandgap cavities employing textured InP membranes. For 1 μm diameter, SiO_2/Ta_2O_5 pillar cavities we obtain cavity quality factors, Q, of 1500 and for membrane cavities, Q values of 850.