Agency for Science, Technology and Research

National University of Singapore

Jinghua Teng

Chengyuan Yang

Ee Jin Teo

Lu Ding

Soo Jin Chua

Xin Wang

Shijie Wang

Zeng Wang

Xiao Ming Goh

Ming Yang

Qing Yang Steve Wu

Jie Deng

Ee Leong Lim

Soo Seng Norman Ang

Xiaosong Eric Tang

Kun Huang

Guang Hui Paul Lim

Kai Dong Ye

Junhao Shawn Tan

Hendrix Tanoto

Andrew Bettiol

Keyan Zang

A method of fabricating an optical lens disclosed herein includes forming a layer of a flat lens structure on a front surface of a substrate, depositing a protective metal layer on the layer of the flat lens structure and on a back surface of the substrate, wherein the protective layer includes chromium, gold, titanium, or nickel, wherein the back surface is located opposite to and away from the front surface having the layer of the flat lens structure, irradiating the protective metal layer at the front surface with a laser to form a channel (i) through the protective metal layer, (ii) through the layer of the flat lens structure and (iii) in the substrate, removing the protective metal layer at the front surface and the back surface of the substrate, and separating the layer of the flat lens structure from the substrate to obtain the optical lens, wherein the channel has a depth defined by a thickness of the substrate remaining at the channel after irradiating the protective metal layer at the front surface with the laser. The optical lens fabricated from the method is also disclosed herein.

Sub-mm flat lens fabrication

Various embodiments may relate to an optical device. The optical device may include a stacked structure having a first surface and a second surface opposite the first surface. The stacked structure may include a plurality of holes or grooves extending from the first surface towards the second surface. The stacked structure may include a transition metal dichalcogenide material (TMDC) material. A thickness of the stacked structure may be of any value less than 100 nm.

Optical device and method of forming the same

Systems and methods for laser stimulated lock-in thermography (LLT) crack detection are provided. The system includes a spatial light modulator and a controller. The spatial light modulator reflects a laser beam to focus the laser beam onto a sample for detection of a crack, hole or scratch. The controller is coupled to the spatial light modulator and controls operation of the spatial light modulator to switch focus of the laser beam onto the sample between a plurality of LLT focus configurations for detection of the crack, hole or scratch on the sample. The method includes using a first one of the plurality of LLT configurations for coarse scanning of the sample to detect a crack, hole or scratch on the sample and, when a crack, hole or scratch is detected on the sample, switching to a second one of the plurality of LLT configurations for fine scanning of the crack, hole or scratch on the sample to determine one or more parameters of the crack, hole or scratch on the sample.

Method for laser stimulated lock-in thermography for micro-crack detection

Reconfigurable laser stimulated lock-in thermography for micro-crack detection

There is provided a holographic security element including a substrate; and an array of nano-reflectors configured to form a pattern on the substrate and to generate a holographic image corresponding to the pattern at a predetermined distance from the substrate when irradiated with a predetermined light source. In particular, the array of nano-reflectors is configured to generate the holographic image at the predetermined distance to have a size that is larger than a size of the pattern. There is also provided a method of forming the holographic security element, and an article having one or more holographic security elements incorporated therein.

Holographic security element and method of forming thereof

A semiconductor device includes a semiconductor substrate having a metasurface layer configured with multiple pairs of finger portions in a repeating arrangement. The multiple pairs of finger portions are electrically configurable to modulate a radiation signal received by the semiconductor device. Each pair of finger portions includes first and second members where the first member is doped with a first dopant and the second member is doped with a second dopant being different to the first dopant. Any two adjacent first or second members are configured to be separated by at least deep subwavelength to enable the repeating arrangement.

Broadband tunable THz wave manipulator and the method to form the same

Various embodiments may relate to a light emitting diode (LED) communication device including a communication interface configured to couple with an electronic device. The LED communication device may also include an electrical interface electrically coupled to the communication interface. The LED communication device may further include a light emitting diode electrically coupled to the electrical interface. The electrical interface may be configured to convert data signals received from the electronic device into driving signals transmitted to the light emitting diode during uplink, and to convert sensing signals received from the light emitting diode into data signals transmitted to the electronic device during downlink. The light emitting diode may be configured to convert the driving signals received from the electrical interface into a plurality of light pulses during uplink, and to convert a plurality of light pulses received by the light emitting diode into the sensing signals during downlink.

Light emitting diode communication device, method of forming and operating the same

A THz photomixer emitter is disclosed. The emitter comprises a photoconductive material, an antenna structure, and an electrode array. The electrode array is disposed such that an electric field associated with photocarriers generated in the photoconductive material is coupled to the antenna for emission of a THz wave via the antenna structure. The electrode array is configured such that an electric field resonance pattern of the electrode array is substantially aligned with an emission field pattern of the antenna structure.

THz photomixer emitter and method

A light emitting diode device (LED) is provided. The LED comprises a first-doped layer on a substrate, an active layer on the first-doped layer, a second-doped layer on the active layer, and a metal layer on the second-doped layer. The second-doped layer is patterned on a surface opposite to the active layer to define a first portion and a second portion. The first portion of the second-doped layer has a first portion thickness constrained for electron-hole pairs in the active layer to couple efficiently to a surface plasmon mode at an interface of the metal layer and the second-doped layer thereby increasing the spontaneous emission rate of the LED. The second portion of the second-doped layer has a second portion thickness sufficient to ensure formation of a p-n junction in the LED.

High speed surface plasmon coupled light emitting diodes

A method of at least partially releasing an epitaxial layer of a material from a substrate. The method comprises the steps of: forming a patterned sacrificial layer on the substrate such that the substrate is partially exposed and partially covered by the sacrificial layer; growing the epitaxial layer on the patterned sacrificial layer by nano-epitaxial lateral overgrowth such that the epitaxial layer is formed above an intermediate layer comprising the patterned sacrificial layer and said material; and selectively etching the patterned sacrificial layer such that the epitaxial layer is at least partially released from the substrate.

Method of at least partially releasing an epitaxial layer

A method of forming a metal contact and passivation of a semiconductor feature, and devices made using the method. The method comprises the steps of forming a dielectric mask on a semiconductor substrate utilising photolithography processes; etching the semiconductor substrate such that one or more features are formed underneath respective portions of the dielectric mask; depositing a passivation layer on the substrate with the dielectric mask in place above the features; subjecting the substrate to an etchant such that the dielectric mask is etched at a higher rate than the passivation layer, whereby portions of the passivation layer deposited on the dielectric mask are lifted off from the substrate; and depositing a metal layer on the substrate including over the remaining passivation layer and exposed portions of the features.

Growing community of inventors

Singapore, Singapore

Jinghua Teng