Tunable Infrared Devices via Ferroelectric Domain Reconfiguration

Abstract

biosensors, [2,3] and photocatalysis [4][5][6] to information processing, [7,8] lithography, [9] and imaging. [10][11][12][13] Despite this wide ranging applicability, upon fabrication plasmonic systems are most often static in their spectral response. Active spectral tuning provides great utility, however, allowing for ultracompact optical systems where a single element provides multiple functionalities. This need is particularly acute in the midand long-wave infrared where optical components are oftentimes large and unwieldy while practical application demands minimization of size, weight, and power. Spectrally tunable IR plasmonics could therefore enable chip-based spectroscopic sensing and hyperspectral imaging in a form factor unattainable by traditional means. [14] To this end, we demonstrate tunable long-wave infrared (LWIR) plasmonic devices based on lead zirconate titanate (PbZr x Ti 1−x O 3 ) ferroelectric bilayers.Tunable IR plasmonic devices have been pursued with several approaches including phase change, [15,16] mechanics, [17] and charge injection. [18][19][20][21] Ferroelectric domain reconfiguration in PZT bilayers is pursued here instead as it offers a suite of capability unattainable using these other approaches, namely: high speed, low power consumption, and a multistate unpowered response (i.e., latchable switching). The following Despite widespread use in sensing, electro-optics, and catalysis, plasmonic elements are typically static in their spectral response. The subwavelength spatial confinement and enhanced electric fields intrinsic to plasmons provide a lever to realize dynamic spectral tunability-and thus multifunctional optical components-as small alterations in their dielectric environment are amplified by these effects. Here, electric-field (DC) control of phonon modes is leveraged in lead zirconate titante (PZT) ferroelectric bilayers to create tunable long-wave infrared (LWIR) plasmonic devices that demonstrate a combination of advantages-speed (>10 kHz), latching, and low-power switching (<1 µJ mm −2 )-unavailable together in approaches reported heretofore. Mechanistically, bias-induced domain reconfiguration alters the phonon energies defining PZT's optical permittivity, which determines the gap plasmon formed within the ferroelectric resting between patterned metal contacts. The utility of ferroelectrics for tunable plasmonic devices is thus demonstrated while highlighting the promise of leveraging phonons for these purposes. Tunable PlasmonicsThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

Controlling the Infrared Dielectric Function through Atomic-Scale Heterostructures

“…An additional major benefit of the XH approach is that it allows for the combination of two materials to achieve a desired IR response, while potentially maintaining their individual mechanical, electrical, or optoelectronic functionality. In many instances, it is necessary to combine other material properties (e.g., an accessible band gap for active tuning 66 or ferroelectric response 67 ) with the polaritonic behavior at a given frequency. For example, while AlN offers a Reststrahlen band that overlaps with the 8−12 μm atmospheric window, its 6 eV bandgap implies that free-carrier-based tuning methods 66 are impractical.…”

Enhanced dielectric, ferroelectric, and optical properties in rare earth elements doped PMN-PT thin films

“…Multifunctional materials have attracted much attention owing to their excellent coupling functions such as electro-mechanical [1][2][3], electro-optical interaction [4,5], and electro-caloric effects [6], for various energy conversion and electronic applications. Recently, on purpose of the combination of piezoelectric (electro-mechanical) and photoluminescence (electro-optical) effects, photoluminescence (PL) characteristics of rare earth (RE) ion doped ferroelectric materials were extensively investigated [5,[7][8][9][10].…”

Broad band infrared modulation using spintronic-plasmonic metasurfaces

“…Phase-change materials as VO 2 also exhibit a change in their optical response, namely an insulator-to-metal transition, which can be driven by either heating the sample or using external laser pump pulses [11]. This change in the permittivity can be exploited, among other uses, for increasing the sensitivity of optical sensors [12][13][14][15], creating switching mono/bi-directional devices [16,17] or fabricating other active infrared devices [18][19][20]. Recently, the family of the giant magnetoresistance (GMR) materials is incorporated into the list of active-control opportunities, demonstrating modulation of mid-infrared response in spintronic-plasmonic platforms using very low magnetic fields [21,22].…”