Nonlinear upconverted thermal emission through difference frequency generation.

Thermal radiation management is of critical importance in energy, sensing, and heat transfer. According to Planck's law, objects at room temperature predominantly emit thermal radiation within the mid- and far-infrared bands. Here, we demonstrated the upconversion of the mid- and far-infrared thermal radiation emitted by second-order nonlinear material to the easily-detectable visible band through a difference frequency process.

Multi-color complex spatial light modulation with a single digital micromirror device.

Spatial light modulators enabling complex light field manipulation has opened up many opportunities in biomedical imaging, holographic display, and adaptive optics. However, traditional spatial light modulators do not allow multi-color operations simultaneously due to their physical constraints, while multi-color modulations are highly desirable in many applications. To overcome this limitation, we demonstrate a multi-color spatial complex light field modulation with a single binary hologram on digital micromirror devices (DMD).

Vibrational modes in an optically levitated droplet.

Levitation by optical tweezers provides a unique non-invasive tool for investigating a microscale object without external perturbations. Here we experimentally levitate a micrometer-sized water droplet in the air using an optical tweezer. Meanwhile, vibrational modes of a levitated water droplet are excited by modulating the trapping laser.

Reciprocal conditions in one-dimensional nonlinear wave systems.

We study wave reciprocity in one-dimensional asymmetric systems constructed by multiple nonlinear δ-function scatters embedded within linear scatters. A general reciprocal condition is proposed, in terms of the rotation symmetry between forward and backward transfer matrices. We then derive various resonance conditions, under which all scatterers behave as merging into either a single nonlinear δ scatter, or a symmetric nonlinear barrier configuration.