Nanoscale Strain Gauges Composed of Microdisk Lasers Embedded in a Flexible Substrate

Compact visible microdisk lasers consisting of InGaP/ InGaAIP multi-quantum wells were fabricated and embedded in a deformable polydimethylsiloxane (PDMS) polymer substrate. In addition to very small device footprint and low-threshold, the wavelength of microdisk lasers can be linearly fine-tuned by stretching the flexible substrate. A smooth wavelength tuning of 1.5 nm and 2.6 nm for microdisk lasers with the diameter of 1.2 μm and 1.5 μm are demonstrated under 36% strain, respectively. The compact tunable visible microdisk lasers can not only function as a novel light source for photonic integrated circuits but also sensitive and skin-attachable gauges in local index and strain detection for stretchable electronics.