Featured Research: Concentric Multi-Reflection Lenses (aka Origami optics)

With up to eight reflections, large ray angles, and a lens shaped more like a lens cap than a tube, so-called Origami Optics allow us to squeeze long focal lengths into a thin package and still collect enough light for fast sharp exposures. Applications may range from compact imagers for micro-UAV surveillance craft to a miniature telephoto lens for future cell phones.

Featured Research: Micro-optic Solar Concentration

High concentration photovoltaic systems (CPV) replace expensive semiconductor materials with inexpensive lenses or mirrors.  The planar micro-optic solar concentrator uses a lens array to collect sunlight and couples the energy into a multimode slab waveguide.  This unique geometry can be fabricated using self-aligned lithography to produce a uniform, high flux output at the PV cell.  Compatibility with roll-to-roll mass fabrication offers a low-cost opportunity for CPV.  

 

Featured Research: Retro-modulation

The retroreflector encodes a signal onto the return beam by adding a modulator to the retroreflector. A commonly used retroreflector is the corner cube retroreflector which simply consists of 3 mirrors at right angles to each other. In our work, we add in its modulation capability by replacing one of the mirrors with a MEMS deformable mirror. This lets us subsequently deform and flatten one of the mirrors, thereby modulating the retroreflected wavefront. Our prototype achieved 10 kHz switching times with 2.4:1 extinctions over a 35° range of incident angles.

Featured Research: Free-Space Optical Demultiplexing and Beam Scanning

In our 2D demultiplexer, we make use of the multiple diffraction orders of a 40 channel arrayed waveguide grating (AWG) demultiplexer by expanding the working wavelength range. By working with a broader band of wavelengths, multiple wavelength channels are given at each output of the demultiplexer. Over a 600 nm bandwidth range, we separated 1092 individual wavelength channels.

Featured Research: Multiband Solar Concentration

Exotic semiconductor materials as well as multijunction solar cells can achieve much higher sunlight conversion efficiencies than traditional silicon solar panels. However these materials are difficult and expensive to manufacture resulting in small surface area cells. Solar concentration utilizes optics to capture light from a large area and condense it onto a small, high-efficiency solar cell. We are developing novel techniques for capturing very large illumination areas without the need for accurate tracking of the solar arc.

Featured Research: Wavefront Sensing

Wavefront sensors are optoelectronic devices used to detect the surfaces of equal phase in a propagating field. A lateral shearing interferometer (LSI) is self-referenced and can be executed using a simple diffraction grating. For integration, the grating is mounted onto a CMOS sensor resulting in a compact and robust wavefront sensor. The device can accommodate a variety of input phase functions by using an adaptive spatial light modulator instead of a fixed grating.

Featured Research: Neonatal Video Laryngoscope

Extremely low birth weight infants regularly require intubation, but cutting edge video laryngoscopes aren't small enough for this population. In a collaboration with the UC San Diego School of Medicine's Division of Neonatology, we worked to design and create a working model neonatal video laryngoscope.

Featured Research: Range Finding

Numerous applications have been the justification for developing many different techniques for ranging (finding the distance from a detector to an object or target). This research is focused on providing ranging for novel mobile robots concurrently designed at UCSD.

Featured Research: Computational Imaging

Computational imaging systems utilize joint optimization of the system's optics and post-processing degrees of freedom for added versatility, performance, and new cabilities.

This section describes our research on