Measurement of the polarization state of light using an integrated plasmonic polarimeter

Abstract

Plasmonics has started to facilitate the replacement of bulky optical components in optical systems by compact nanometallic elements that perform the same function. This allows for a natural and very dense integration with electronic devices. In this vein, we present a silicon (Si) photodetector integrated with a set of plasmonic structures that can be used as either a broadband linear-Stokes polarimeter or a narrowband fullStokes polarimeter capable of determining the complete state of polari zation of a light beam. At a probe-wavelength of 830 nm, our experimental results show contrast ratios of 25 and 1.13 for orthogonal linear and circular states of polarization, in good agreement with simulations. The resulting device is lightweight, orders of magnitude smaller than conventional polarimeters, and mechanically robust. For these reasons, there promises to be a wide range of applications including polarimetric imaging and sensing.Keywords: Surface plasmon; polarization selective devices; polarimetry.Polarization is a property of light that describes the vector nature of its electric fi eld oscillations. Since polarization information is not correlated with the intensity or spectral information of light, use of polarized light has added superb capabilities to a wide range of applications including optical communications, imaging, microscopy, and sensing. In such applications, the state of polarization is typically monitored with the help of bulky optical components. It is by now wellestablished that nanometallic (i.e., plasmonic) structures can be engineered to produce an optical response that is strongly polarization-dependent [1 -9] . Very recently, the use of plasmonic crystals in free-space polarimetric systems has even been demonstrated [10,11] . Here, we show how to fully integrate plasmonic polarimetry functions with a Si-based photodetector. Such an integrated plasmonic polarimeter enables an accurate measurement of the complete state of polarization of light. Whereas conventional polarimetry approaches rely on the use of large optical components such as rotating polarizers and retardation wave plates, [12,13] this work shows that a compact platform can achieve the same functions. This work adds to a growing body of literature where plasmonic elements can be integrated with semiconductor elements to produce photodetectors with enhanced optical responses, integration advantages, or new, built-in optical functionalities [14 -17] .A set of four parameters is required to completely describe the state of polarization of an arbitrary polarized electromagnetic wave [12] . Experimentalists commonly use the Stokes parameters (S 0 , S 1 , S 2 , S 3 ) for this purpose as these parameters are conveniently measured as a sum or difference of measurable light intensities after light passes through polarization sensitive fi lters [18] . We have designed a compact plasmonic photodetector structure with which these parameters can be quantifi ed in a quick and convenient fashion through a set of photocurrent mea...

Universal method for the synthesis of arbitrary polarization states radiated by a nanoantenna

“…This universal method is a very versatile and convenient way of achieving broadband polarization synthesis over the whole Poincaré sphere with a single nanoantenna element. The reciprocal setup, detecting different polarizations from the received amplitude and phase of the two output waveguides of a receiving nanoantenna, could be used for fast and integrated ellipsometers/polarimeters [25][26][27] and for the sorting of polarized photons impinging into a single nanoantenna. In general, as described in the supplementary information, the antenna could be designed for the ideal sorting of polarization states that are not necessarily orthogonal [28].…”

Circularly Polarized Light Detection with Hot Electrons in Chiral Plasmonic Metamaterials

“…It is also important to note that although our device responsivity is still low compared with non-chiral InGaAs or Ge detectors (B900 mA W À 1 ) in this wavelength range, the later is not able to distinguish CPL. A similar functionality could be achieved by integrating the chiral metamaterial with such semiconductors, however, this does not necessarily produce high polarization selectivity 19 (Supplementary Fig. 7; Supplementary Note 3) even though a higher quantum efficiency could be realized.…”

“…Furthermore, surface plasmon resonances offer new insights into creating artificial media, or metamaterials, with interesting optical properties such as strong chirality 17,18 that is several orders of magnitude larger than that of chiral molecules. A number of chiral metamaterials based on plasmonic building blocks including spiral 19 , fish-scale metamaterials 20 , helix 12,21,22 , oligomers 23 and twisted metamaterials 24,25 have been demonstrated to date using both bottom-up 21,26 and top-down approaches 12,[23][24][25] . In addition, Archimedes spiral designs have been utilized to enable chiral-selective field enhancements in semiconductors, leading to selective photocurrent for LCP and RCP light, with an experimentally measured ratio of 1.13 (ref.…”

Design and implementation of nanoantennas on integrated guides and their application on polarization analysis and synthesis.

“…Notice that polarimeters relying upon plasmonic nanoresonators [129,130] and metasurfaces [131,132,133,134,135] have been recently demonstrated. Despite their remarkable performance, they use metallic nanostructures with complex shapes, which besides introducing undesired losses, are not typically compatible with standard semiconductor fabrication technologies.…”

“…While apparently unrelated, the propagation direction and the polarization of a light beam may be strongly connected via spin-orbit interactions (SOI) of light [126,67,127,128,129,130,131,132,133,134,135,136]. Indeed, SOI is ultimately responsible for the unidirectional propagation of guided waves controlled by the spin of an excitation source [66,137], as shown in Chapter 2.…”