Introduction to the Issue on Photonics for Sensing

The papers in this special section address the use of photonics for sensing applications. Light has long been used for sensing, metrology, imaging, and measurement in human history. The inventions of semiconductor sources and detectors, optical fibers and integrated optical waveguides in the last century have led to the emergence of photonics. The papers cover a wide variety of topics in the design, characterization, packaging and demonstration of new photonic devices, structures, functional materials, fabrication methods, and signal processing principles for sensing various physical, chemical and biological parameters. The sensing scales range from nanometers based on tip enhanced Raman scattering and quantum dots to kilometers based on distributed Raman or Brillouin scattering in optical fibers. The electromagnetic spectra cover microwave, terahertzrange, deep ultraviolet (UV), visible, and mid-infrared (IR).