Low Thermal Impedance of Substrate-Free Metal Cavity Surface-Emitting Microlasers

The thermal impedance of a substrate-free metal cavity surface-emitting microlaser is measured. The lasing wavelength shifts with temperature at a ratio of 4.367 × 10
^-2
nm/°C. An extremely low thermal impedance below 1.730°C/mW is extracted for this microlaser with a 1.0-μm radius and 3.5-μm height in the temperature window of 20°C -80°C. The full metal coverage, substrate-free configuration, and metal bonding lead to efficient heat removal.