2014 IEEE Photonics Conference

I will discuss my group's recent work on rethinking microscopy from the ground up. I will report on a self-imaging petri dish technology (ePetri) which is capable of streaming microscopy-level live cell culture images directly out of the incubator. I will also discuss our recent work on Fourier Ptychographic Microscopy which enables a standard microscope to push past its physical optical limitatio... View full abstract»

Vesicles comprise of a thin membrane that encapsulates a liquid- or gas-filled reservoir [1, 2]. They are formed via the self-assembly of amphiphilic molecules or proteins under appropriate pressure, temperature and concentration conditions (Fig. 1a). By controlling such conditions, vesicles may be engineered in a variety of sizes, from a few 10's of nm up to 100's μm in diameter. View full abstract»

Simultaneous spatial and temporal focusing (SSTF) of femtosecond pulses was originally conceived as a novel method for increasing the field-of-view in multiphoton imaging applications. Multiphoton imaging with SSTF deviated from traditional nonlinear systems in that it enabled the use of low numerical aperture beams to be used to increase the field-of-view, but retain the axial sectioning of a hig... View full abstract»

From touch screens and telecommunications networks, to driving, reading, and enjoying theater, light-based optical information features in much of how we interact with the world. As health care needs advance, optical technologies are becoming increasingly popular, both as complementary and standalone modalities. Since its inception nearly three decades ago, optical coherence tomography (OCT) has e... View full abstract»

The spatial and temporal coherence of optical fields are basic properties that have been successfully exploited in biomedical optics. I will discuss our use of optical coherence tomography, an imaging modality that exploits low temporal coherence, to explore microfluidic-scale pulmonary and cardiovascular physiology. I also will discuss our work in the targeted design of desirable spatial coherenc... View full abstract»

Varifocal lenses for visible wavelength range applications are fabricated using KTa_1-xNb_xO₃crystals. The unexpected beam distortion caused by the aberration of the lenses is greatly reduced by suppressing electron injection. View full abstract»

We have developed the Interferometric Reflectance Imaging Sensor (IRIS) for label-free, high throughput, high sensitivity and dynamic detection of molecular binding on a solid surface. Recently, we have demonstrated IRIS with the ability to detect single nanoscale particles. To detect and size nanoparticles, IRIS shines light from visible LED sources on nanoparticles bound to the sensor surface, w... View full abstract»

We propose a new cancer treatment technique in which graphene nanoflakes and carbon nanotubes operate as a self-assembled cluster of spasers near cancer cells causing selective destruction of them by an amplified electric field. View full abstract»

We fabricated solid thin film composed of deoxyribonucleic acid (DNA) complexes based on cetyltrimethylammonium (DNA-CTMA). We developed a re-crystallization process that can reduce the hydroxyl contents significantly, which were confirmed by the Raman spectra measurements. DNA-CTMA film was deposited on a polydimethylsiloxane (PDMS) channel to form a ridge waveguide. View full abstract»

In this paper, the emission characteristics based on photonic crystal effect of nanocolumn LEDs are discussed. The device exhibited electroluminescence (EL) and photoluminescence (PL) spectra with the narrow linewidth as well as with the sharp radiation beam profile, when the photonic band edge was controlled to be coincident with bandgap of the InGaN/GaN MQW emission region. View full abstract»

We report a significant improvement in the electrical characteristic of compositionally graded InGaN/GaN multiple-quantum-well (MQWs) micro-LED. The efficiency droop in this device occurred at ~20 times higher injection levels (~275 A/cm²) compared to a conventional step-MQWs microLED (~14 A/cm²). View full abstract»

When the emission spectrum of the powder state is adopted, the simulated optical properties show a remarkable discrepancy from those of the fabricated LED package. We suggest that the discrepancy originates from the absorption of Stokes shifted light by a phosphor. View full abstract»

We found it is feasible to reduce RMS power over 30% after of applying alternating driving scheme with filter circuitry for a 2×2 matrix white organic light-emitting diodes (WOLED) lighting unit by equivalent circuitry simulation. View full abstract»

Silicon photonics are an attractive technology for global interconnects in manycore processors. However, they come with significant laser power consumption. Turning off underutilized portions of the interconnect can save 62-92% of the laser power. View full abstract»

We report design and fabrication of photonic crystal (PC) Si membrane reflectors with integrated inplane couplers (Si MR-Coupler) based on Fano resonance effect. The measured results show the Si MR-Coupler has a 99% reflection and > 0.22% in-plane coupling efficiency. View full abstract»

The electro-optic (EO) waveguide modulators based on the high EO active polymer are designed and fabricated. We show two types of the EO polymer waveguides. One is the waveguide having traditional core and clad structure, which shows a few volts of the half-wavelength voltage (Vπ) and 50 GHz bandwidth property. Another waveguide is the hybrid type, which is composed of the TiO2 View full abstract»

We analyze and improve the crosstalk between adjacent output-ports in Bragg reflector waveguides array-based wavelength selective switching. Crosstalk below -23 dB is obtained in a 200-port waveguide array with a pitch of only 30 μm. View full abstract»

We present the fabrication and the characterization of waveguides made of a nematic liquid crystal infiltrated in PDMS channels. The molecular orientation inside the waveguides allows only 0.3 dB variation of light transmission versus polarization. View full abstract»

Metal oxide semiconductors are developing rapidly.1The high mobility of the oxides enables their use for OLED displays or high speed LCD switching. Solution deposition methods of fabrication are attractive for low cost manufacturing of large area electronics and so there is interest in the formation of the oxide semiconductors from solution.2InGaZn oxide semiconductor TFTs we... View full abstract»

Quantum dots (QDs) backlight brings several advantages to LCDs, including wider color gamut, higher light efficiency, enhanced ambient contrast ratio, and over 100X smaller color shift. The prime time for QD-enhanced LCDs is around the corner. View full abstract»

An oxide-TFT-driven flexible AMOLED display using inverted OLEDs was fabricated. The fabricated TFT backplane exhibited good electrical characteristics, and we confirmed the display could show color moving images. View full abstract»

A novel coupling approach for single mode VCSELs and planar optical waveguides is presented. The coupling is based on the embedding of the VCSELs inside the substrate and the adaptive fabrication of waveguides on top. View full abstract»

We extend our state-of-the-art multi-mode polymer waveguide technology to single-mode operation at a wavelength of 1300 nm and demonstrate the potential of this single-mode optical PCB technology for the assembly of silicon photonics chips. View full abstract»

We demonstrate that graded-index (GI) profiles in square-core waveguides improve the loss at 45-degree mirrors on its ends over the SI-core waveguides. We also fabricate and characterize the mirror on GI “circular”-core waveguides. View full abstract»

We demonstrate a photomask-free fabrication for single-mode polymer optical waveguides using the Mosquito method. In fabricating the waveguides, an inorganic-organic hybrid resin is applied to decrease the carbon-hydrogen absorption loss at 1550-nm wavelength. View full abstract»