Vertically coupled double-microdisk lasers composed of InGaAs quantum dots-in-a-well active layers

We report the epitaxy, fabrication, and measurement of vertically coupled double-microdisk lasers using InGaAs quantum dots-in-a-well as the optical gain material. The bonding and anti-bonding photonic molecule laser modes are simultaneously observed at room temperature (T = 300 K). The optical coupling is confirmed by measuring the double disks for three different air gaps of 100 nm, 200 nm, and 480 nm, respectively. The coupling strengths for the photonic molecule bonding mode M-1,9(B) and anti-bonding mode M-1,9(A) between the adjacent microdisks are equal to 17.4 THz for 100 nm air gap, and 5.2 THz for 200 nm air gap, respectively. The refractive index sensing experiments show the lasing wavelength sensitivity of 60 nm/RIU for the vertically coupled double-microdisk laser of 100 nm air gap. Published by AIP Publishing.