RESUMEN
We have developed a new, to the best of our knowledge, femtosecond laser spatiotemporal imaging technique, named asynchronous wide-field transient absorption microscopy (AWTAM), which does not require phase synchronization between an optical chopper and a complementary metal-oxide-semiconductor (CMOS) camera. By presenting a theoretical scheme, an image reconstruction algorithm, and experimentally imaging the photocarrier diffusion process in a 2D layered semiconductor, our technique has been comprehensively demonstrated. Our technique is widely applicable for fundamental photo-physical research and industrial applications, with the advantages of lower hardware cost as well as higher imaging speed.
RESUMEN
The potential of whispering-gallery-modes (WGMs) microcavities in sensing applications has been being released continuously with improvements from various aspects. Introducing smart materials and structures into the WGMs microcavities based sensing systems are an effective approach to promote their applications in real world. Here, we propose a smart grating as the coupling setup to a WGMs microcavity of polystyrene microsphere to enhance the responses to chemical and thermal stimulations. The changes of the coupling distance due to the deformation of the smart grating induce additional increments to the intrinsic wavelength shifts of the WGMs of the microcavity, which is proved to be the mechanism of the response enhancements. We use two-photon lithography based "lab on fiber" technology to realize the device and the demonstration of the response enhancements. Our results may be of great significance to the design of the WGMs microcavity based chemical and temperature sensors.