Thermo-optically tuned single-mode limaçon microlaser on quantum-dots

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Thermo-optically tuned single-mode limaçon microlaser on quantum-dots

Journal of Physics D: Applied Physics. 2026. Vol. 59. No. 30. P. 305103.

Образцова А. А., Ivanov K., Moiseev E., Fedosov I. S., Makhov I., Kryzhanovskaya N., Zhukov A.

We demonstrate a thermo-optically tunable microlaser based on an InGaAs/GaAs quantum-dot (QD) active region employing a deformed limaçon-shaped cavity. The asymmetric geometry effectively lifts the degeneracy of high-Q whispering-gallery modes, enabling single-mode lasing. A side-mode suppression ratio exceeds 25 dB over a wide current range. Under continuous-wave electrical pumping, the device achieves a peak output power of ∼0.4 mW, which is 1.5 times higher than that of a circular microdisk of comparable size, due to enhanced directional out-coupling. By exploiting self-heating via injection current control, we realize continuous wavelength tuning over a mode-hop-free range of 4.6 nm with a tuning coefficient of ∼0.3 nm mA−1. In addition, complementary temperature-dependent measurements under pulsed current injection with externally controlled stage heating were performed to independently characterize the thermal response of the device. These measurements reveal a linear wavelength shift with a thermal tuning coefficient of 0.073 nm K−1. Experimental results are supported by finite-element method simulations, which confirm a significant reduction in the number of competing cavity modes as the cavity deformation parameter increases. The combination of single-mode operation, efficient power output, and electrically controlled thermo-optic tuning makes these limaçon-shaped QD microlasers promising candidates for compact, tunable light sources in photonic integrated circuits and sensing applications.

Research target: Physics

Language: English

DOI

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