Abstract: Vertical-cavity surface-emitting laser (VCSEL) structures are described which enable their use as widely wavelength-swept coherent light sources and multiple-wavelength VCSEL arrays. Three general configurations are described: (a) a semiconductor-cavity-dominant (SCD) with high reflection at the semiconductor-air interface, (b) an extended-cavity (EC) design in which reflections at the semiconductor-air interface is reduced to insignificance compared to the SCD design with a refractive index-matched layer (i.e., AR layer) so the entire structure resonates as one cavity, and (c) an air-cavity-dominant (ACD) design which facilitates a larger field confinement in the air gap, and the increased field confinement causes the air gap to be the dominant cavity.

Abstract: An optical sensing platform with an array of sensors, a laser or broadband light source and an optical detector that utilizes surface plasmon resonance based transduction and optical detection is provided. The sensor structure of the platform has a low index support layer, a high contrast grating, a low index spacer and a thin metal film with a target recognition element. The surface plasmon resonance based sensor uses surface plasmon waves to detect changes on the surface of the sensor when a target interacts with the target recognition element. The binding of the target with a recognition element receptor will induce changes in the refractive index of the metal layer, which changes the resonance wavelength of the plasmon wave on the sensor surface, which is used to measure or observe the reaction.

Abstract: A color changing or beam steering photonic device, which combines a high contrast metastructure (HCM) having a plurality of high index grating structures, into a low index membrane. In response to physical (or electrical) deformation of the membrane the low index gaps between adjacent grating bars changes which results in changing reflectance and transmission angles for steering a single wavelength of light and for causing a color change in said photonic device when subject to multiple light wavelengths. Deformation can result from direct physical stimulus, conversion from electrical or thermal to physical, and so forth. Refractive index change can also be initiated by carrier injection through electrodes. The apparatus is exemplified for use in color displays, beam steering, labeling micro entities, mechanical deformation sensing, camouflage, anti-counterfeiting, and other fields.

Abstract: Vertical-cavity surface-emitting laser (VCSEL) structures are described which enable their use as widely wavelength-swept coherent light sources and multiple-wavelength VCSEL arrays. Three general configurations are described: (a) a semiconductor-cavity-dominant (SCD) with high reflection at the semiconductor-air interface, (b) an extended-cavity (EC) design in which reflections at the semiconductor-air interface is reduced to insignificance compared to the SCD design with a refractive index-matched layer (i.e., AR layer) so the entire structure resonates as one cavity, and (c) an air-cavity-dominant (ACD) design which facilitates a larger field confinement in the air gap, and the increased field confinement causes the air gap to be the dominant cavity.

Abstract: An optical sensing platform with an array of sensors, a laser or broadband light source and an optical detector that utilizes surface plasmon resonance based transduction and optical detection is provided. The sensor structure of the platform has a low index support layer, a high contrast grating, a low index spacer and a thin metal film with a target recognition element. The surface plasmon resonance based sensor uses surface plasmon waves to detect changes on the surface of the sensor when a target interacts with the target recognition element. The binding of the target with a recognition element receptor will induce changes in the refractive index of the metal layer, which changes the resonance wavelength of the plasmon wave on the sensor surface, which is used to measure or observe the reaction.

Abstract: A color changing or beam steering photonic device, which combines a high contrast metastructure (HCM) having a plurality of high index grating structures, into a low index membrane. In response to physical (or electrical) deformation of the membrane the low index gaps between adjacent grating bars changes which results in changing reflectance and transmission angles for steering a single wavelength of light and for causing a color change in said photonic device when subject to multiple light wavelengths. Deformation can result from direct physical stimulus, conversion from electrical or thermal to physical, and so forth. Refractive index change can also be initiated by carrier injection through electrodes. The apparatus is exemplified for use in color displays, beam steering, labeling micro entities, mechanical deformation sensing, camouflage, anti-counterfeiting, and other fields.

Abstract: A vertical optical coupler which redirects light transmission in response to the interaction between a sub-wavelength high contrast grating (HCG) having a plurality of spaced apart segments of grating material which is optically coupled to a waveguide. For a selected set of material, grating geometry, gaps and spacing, the light directed at a normal incidence into the optical coupler is angularly displaced in traveling in the optical waveguide, while light directed along the optical waveguide is angularly displaced in being output at normal incidence from the optical coupler. The coupler is integrated into a number of device embodiments, including: a coupler between angularly displaced waveguides, lasers, light emitting diodes (LEDs) and solar cells.

Abstract: A surface emitting laser apparatus is formed using a patterned silicon-on-insulator (SOI)-like substrate which is patterned with a buried sub-wavelength high contrast grating and adapted for bonding of a half-VCSEL device containing at least an active region and an upper mirror, to create a VCSEL. The wavelength of the VCSEL, or any individual VCSEL within an array of VCSEL devices, can be set in response to changing HCG characteristics of the lower mirror in the SOI-like substrate, or in the region above the lower mirror within the half-VCSEL. The inventive VCSEL device and fabrication method are beneficial for a number of application and devices.

Abstract: Monolithically integrated optical resonators are disclosed. An optical resonator may be a nanopillar optical resonator that is formed directly on a substrate and promotes a helically-propagating cavity mode. The helically-propagating cavity mode may result in significant reflection or, total internal reflection at an interface of the nanopillar optical resonator and the substrate even if refractive indices of the nanopillar optical resonator and the substrate are the same or similar. As a result, strong optical feedback, and thus strong resonance, may be provided in the nanopillar optical resonator.

Abstract: A short-cavity semiconductor laser heterostructure, such as a vertical-cavity surface emitting laser (VCSEL) comprising a laser cavity having upper and lower surfaces and an active region disposed between the upper and lower surfaces for generating light and emitting light substantially perpendicular to the upper surface of the cavity, an upper high contrast grating (HGC) mirror disposed adjacent to the upper surface of the laser cavity, and a lower HCG mirror disposed adjacent to the lower surface of the laser cavity.

Abstract: Embodiments of a monolithically integrated optical resonator are disclosed. In one embodiment, the optical resonator is a nanopillar optical resonator that is formed directly on a substrate and promotes a helically-propagating cavity mode. The helically-propagating cavity mode results in significant reflection or, in some embodiments, total internal reflection at an interface of the nanopillar optical resonator and the substrate even if refractive indices of the nanopillar optical resonator and the substrate are the same or similar. As a result, strong optical feedback, and thus strong resonance, is provided in the nanopillar optical resonator.

Abstract: A dual usage HCG VCSEL detector is provided with a high contrast grating (HCG) reflector first reflector that has a two dimensional periodic structure. The two dimensional structure is a periodic structure that is a symmetric structure with periodic repeating. The symmetrical structure provides that polarization modes of light are undistinguishable. A second reflector is in an opposing relationship to the first reflector. A tunable optical cavity is between the first and second reflectors. An active region is positioned in the cavity between the first and second reflectors. The photodetector is polarization independent. An MQW light absorber is included converts light to electrons. A dual usage HCG VCSEL-detector includes a high contrast grating (HCG) reflector first reflector, and a second reflector in an opposing relationship to the first reflector. A tunable optical cavity is between the first and second reflectors. An active region is positioned in the cavity between the first and second reflectors.

Abstract: A photodetector is provided with a high contrast grating (HCG) reflector first reflector that has a two dimensional periodic structure. The two dimensional structure is a periodic structure that is a symmetric structure with periodic repeating. The symmetrical structure provides that polarization modes of light are undistinguishable. A second reflector is in an opposing relationship to the first reflector. A tunable optical cavity is between the first and second reflectors. An active region is positioned in the cavity between the first and second reflectors. The photodetector is polarization independent. An MQW light absorber is included converts light to electrons.

Abstract: The present disclosure provides a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400° C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (?m) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6° to 9° tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.

Abstract: Planar lenses and reflectors are described comprising subwavelength high-contrast gratings (HCG) having high index of refraction grating elements spaced apart from one another in straight and/or curved segments and surrounded by low index material. The high-contrast grating is configured to receive an incident wave which excites multiple modes within the high-contrast grating and is focused for reflection and/or transmission by said high contrast grating. The width of the high contrast grating bars vary along a distribution direction of the grating bars which is perpendicular to the length of the grating bars and/or varies along the length of one or more grating bars to focus said reflection and/or transmission. The HCG is configured to provide double focusing, whose use is exemplified within a vertical cavity surface emitting laser (VCSEL) structure using focusing HCG structures for both the top and bottom mirrors.

Abstract: The present disclosure provides a method for a catalyst-free growth mode of defect-free Gallium Arsenide (GaAs)-based nanoneedles on silicon (Si) substrates with a complementary metal-oxide-semiconductor (CMOS)-compatible growth temperature of around 400° C. Each nanoneedle has a sharp 2 to 5 nanometer (nm) tip, a 600 nm wide base and a 4 micrometer (?m) length. Thus, the disclosed nanoneedles are substantially hexagonal needle-like crystal structures that assume a 6° to 9° tapered shape. The 600 nm wide base allows the typical micro-fabrication processes, such as optical lithography, to be applied. Therefore, nanoneedles are an ideal platform for the integration of optoelectronic devices on Si substrates. A nanoneedle avalanche photodiode (APD) grown on silicon is presented in this disclosure as a device application example. The APD attains a high current gain of 265 with only 8V bias.

Abstract: A saturable absorber (SA) based on a high-contrast grating (HCG) having a buried layer of quantum structures for absorption, and which is particularly well suited for use in a mode-locked application. The HCG-SA provides three times the bandwidth compared with traditional DBR structures, while exhibiting a lower saturation fluence due to the field enhancement inside the grating. Varying grating bar width over one or two axis provides lensing effects on the optical output, while chirping of the period and duty cycle changes optical phase relationships. Novel VCSEL embodiments with external or internal cavities are described using the HCG-SA.

Abstract: Enhanced reflectivity High-Contrast Gratings are described which operate in different medium. An HCG is described with a deep/buried metallization layer separated at a distance of least three to four grating thicknesses from the grating. Reflective bandwidth of the HCG is substantially increased, such as by a factor or five, by inclusion of the deep/buried metallization layer. An HCG is described which provides high reflectivity, even when embedded into materials of a moderate to high index of refraction, such as semiconductor material. Vertical cavity surface emitting laser embodiments are described which utilize these reflectivity enhancements, and preferably utilize HCG reflectors for top and/or bottom mirrors.

Abstract: Optical waveguides using segmented periodically-spaced high contrast gratings bounding a hollow core propagation region on at least two sides. Incident light is received in a hollow waveguide (HW) region (core) between opposing HCG faces which provide lateral confinement in response to glancing reflections of the incident light beam from high refractive index segments of the HCG as it traverses the core. Embodiments are described for planar waveguides (1D) having a planar core between two planar HCGs, as well as 2D waveguides, such as having rectangular segments of the HCG through which light is propagated. Additionally, other configurations of HCG-HW, including those having arbitrary incidence and azimuth, angled HCG segments, propagation in a direction which is transverse, or alternatively parallel, to the segments of the HCG.

Abstract: Planar lenses and reflectors are described comprising subwavelength high-contrast gratings (HCG) having high index of refraction grating elements spaced apart from one another in straight and/or curved segments and surrounded by low index material. The high-contrast grating is configured to receive an incident wave which excites multiple modes within the high-contrast grating and is focused for reflection and/or transmission by said high contrast grating. The width of the high contrast grating bars vary along a distribution direction of the grating bars which is perpendicular to the length of the grating bars and/or varies along the length of one or more grating bars to focus said reflection and/or transmission. The HCG is configured to provide double focusing, whose use is exemplified within a vertical cavity surface emitting laser (VCSEL) structure using focusing HCG structures for both the top and bottom mirrors.