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Half-Ring Microlasers Based on InGaAs Quantum Well-Dots with High Material Gain
We report on half-ring lasers that are 100–200 um in diameter and are fabricated by cleaving
the initial full rings into halves. Characteristics of the half-ring and half-disk lasers fabricated from the
same wafer are compared. The active area of the microlasers is based on the quantum heterostructures
of mixed (0D/2D) dimensionality, referred to as quantum well-dots with very high material gain.
Half-ring lasers show directional light emission and single-mode lasing near the threshold. A maximal
continuous-wave output power of 76 mW is achieved for a half-ring that is 200 um in diameter. Halfrings
demonstrate better wall-plug efficiency as compared to half-disks. Lasing in pulse mode is
observed up to 140 C, the characteristic temperature is 100–125 K, depending on the half-ring size.
P-side down bonding onto Si-board significantly improves power and temperature characteristics. In
CW mode, lasing is maintained up to 97 C, limited by active-area overheating.