The constituent elements of metasurfaces may be designed with explicit polarization dependence, making metasurfaces a fascinating platform for new polarization optics. In this work we show that a metasurface grating can be designed to produce arbitrarily specified polarization states on a set of defined diffraction orders given that the polarization of the incident beam is known. We also demonstrate that, when used in a reverse configuration, the same grating may be used as a parallel snapshot polarimeter, requiring a minimum of bulk polarization optics. We demonstrate its use in measuring partially polarized light, and show that it performs favorably in comparison to a commercial polarimeter. This work is of consequence in any application requiring lightweight, compact, and low-cost polarization optics, polarimetry, or polarization imaging.

The gain spectra of a submonolayer (SML) InGaAs∕GaAs quantum dot (QD) laser working at 30°C were measured using the Hakki–Paoli method. It is found that the maximum modal gain of QD ground states is as high as 44cm−1 and no gain saturation occurs below the threshold at the lasing wavelength of 964.1nm. When the injection current is about 0.98 times the threshold, the gain spectrum becomes symmetric with respect to the lasing wavelength, and zero-linewidth enhancement factor is observed. These properties are attributed to the high density and the high uniformity of SML QDs in our laser diode.

In-line polarimeters perform nonterminating measurements of the polarization state of light by sampling only a small part of the total light intensity. In-line polarimeters are used in applications such as polarization state generators and in optical communications. Current polarimeters use multiple optical components in sequence for polarization analysis and therefore often become bulky and expensive. Here, we experimentally demonstrate the operation of compact fiber-coupled polarimeters with high sampling rates, operating at telecom wavelengths, each polarimeter comprising a single ultra-thin metasurface aligned to four photodetectors. We compare two configurations of such metasurface polarimeters, with in-plane and out-of-plane detection, respectively. The metasurface polarimeters reported here show excellent agreement with commercial polarimeters and cover a bandwidth of at least 100 nm.

Metasurfaces—subwavelength arrays of phase-shifting elements—present new possibilities for polarization optics and polarimetry. In particular, a periodic, polarization-sensitive metasurface diffraction grating can enable full-Stokes imaging polarimetry with a single polarization-sensitive component. In this work, we show that a suitably-designed metasurface grating can serve as a polarimetric “attachment” to an existing intensity-only imaging system, converting it into one capable of full-Stokes imaging polarimetry. Design rules and tradeoffs governing this adaptation are described and demonstrated using a machine vision imaging system as an example.