Dynamic Focusing with High-Quality-Factor Metalenses

Abstract

Metasurface lenses provide an ultrathin platform in which to focus light, but weak light–matter interactions limit their dynamic tunability. Here we design submicron-thick, ultrahigh quality factor (high-Q) metalenses that enable dynamic modulation of the focal length and intensity. Using full-field simulations, we show that quality factors exceeding 5000 can be generated by including subtle, periodic perturbations within the constituent Si nanoantennas. Such high-Q resonances enable lens modulation based on the nonlinear Kerr effect, with focal lengths varying from 4 to 6.5 μm and focal intensities decreasing by half as input intensity increases from 0.1 to 1 mW/μm2. We also show how multiple high-Q resonances can be embedded in the lens response through judicious placement of the perturbations. Our high-Q lens design, with quality factors 2 orders of magnitude higher than existing lens designs, provides a foundation for reconfigurable, multiplexed, and hyperspectral metasurface imaging platforms.

Metasurface-empowered spectral and spatial light modulation for disruptive holographic displays

“…109 Furthermore, high- Q phase gradient metasurfaces have been utilized to exhibit dynamic optical responses. 110 Using the optical Kerr effect, high- Q metalenses have been numerically proposed, exhibiting controllable focal lengths and intensities. A high- Q GMR is applied to achieve an efficient nonlinear response.…”

Recent Progress on Ultrathin Metalenses for Flat Optics

“…In one proposed design, dynamic modulation of focal length and intensity of a metalens can be achieved by varying the power of the incident beam (Klopfer et al, 2020). The design concentrates the nonlinear Kerr effect of silicon (Leuthold et al, 2010) to continuously vary the focal length over a range of 2.5 mm.…”

Angular‐Multiplexing Metasurface: Building Up Independent‐Encoded Amplitude/Phase Dictionary for Angular Illumination

“…With the long‐lasting dream of at‐will light manipulation, the invention of metasurfaces with subwavelength‐featured antennas enables a revolutionized way to achieve more degree of freedom in light control. [ 1,2 ] During the last decade, many previous endeavors on metasurfaces could exhibit great promise for achieving various practical applications including beam shaping, [ 3–6 ] achromatic lens, [ 7–10 ] hologram, [ 11–17 ] nanoprinting, [ 18–22 ] invisibility cloaking, [ 23,24 ] optical information multiplexing/encryption, [ 25–27 ] and programmable metasurfaces. [ 28–32 ] So far, the majority of controllable optical parameters have been extensively explored and created for new completely independent freedom in light manipulation and optics multiplexing, such as wavelength, [ 33–36 ] polarization, [ 37–30 ] orbital angular momentum (OAM), [ 14–16 ] forward/backward illumination direction (+/‐) [ 39–41 ] as well as the initial phase of the light field.…”

“…With the long-lasting dream of at-will light manipulation, the invention of metasurfaces with subwavelength-featured antennas enables a revolutionized way to achieve more degree of freedom in light control. [1,2] During the last decade, many previous endeavors on metasurfaces could exhibit great promise for achieving various practical applications including beam shaping, [3][4][5][6] achromatic lens, [7][8][9][10] hologram, [11][12][13][14][15][16][17] nanoprinting, [18][19][20][21][22] invisibility cloaking, [23,24] optical information multiplexing/encryption, [25][26][27] and programmable metasurfaces. [28][29][30][31][32] So far, the majority of controllable optical parameters have been extensively explored and created for new to show independent display channels for nanoprinting and meta-holography: 1) two independent holographs 2) two independent nanoprinting images, 3) one holograph with the other nanoprinting image for two designed angular channels.…”