Jame J. Yang's research while affiliated with University of Miami and other places

We report a multispectral imaging microscope with dynamic spectral reconfiguration capability. It operates based on a spatial filtering principle. The objective lens images the test specimen onto a dispersive grating surface. A dynamic spatial filter located at the Fourier plane of the 4-f lens group is used to select the desired spectral channel and spectral width for each spectral image diffracted by the grating. The reconfiguration capability enables the optimal spectral band selection for a specific application without hardware component modification. Successful experimental results validate the microscopic multispectral imaging configuration for practical applications. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Keywords (in text query field) Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

We successfully demonstrated a multispectral remote sensing system based on our reported spectral imaging design. Dynamic spatial filters such as electronically selected slits were used to select desired bandpass spectrum at a Fourier plane of its optical system. Minimum 9 nm spectral resolution and 0.6° field of view has been achieved. In addition, compact prototype system packaging with a dimension of 17×11×8 inch has been attained. The real-time spectral imaging system capable of wide spectral band operation with simultaneous fine spectral resolution is particularly useful for a variety of defense, medical, and environmental monitoring applications.

Surveillance and tracking of targets such as sensor fused warheads (SFWs) and unmanned aerial vehicles (UAVs) has been a challenging task, especially in the presence of multiple targets moving at a relatively fast speed. Due to the insufficient wavelength resolution, conventional radar technology may fail to resolve closely located targets or lack spatial resolution for specific target identification. There is a need for the development of an innovative sensor that is able to recognize and track closely related targets. To address this need, we have developed a target sensor that combines vision and laser ranging technologies for the detection and tracking of multiple targets with wide viewing angle and high spatial resolution. Using this sensor, regions-of-interest (ROIs) in the global scene are first selected, and then each ROI is subsequently zoomed with vision technique to provide high spatial resolution for target recognition or identification. Moreover, vision technique provides the azimuth and elevation angles of targets to a laser range finder for target distance determination. As a result, continuous three-dimensional target tracking can be potentially achieved with the proposed sensor. The developed sensor can be suitable for a wide variety of military and defense related applications. The design and construction of a proof-of-concept target tracking sensor is described. Basic performance of the constructed target tracking sensor including field-of-view, resolution, and target distance are presented. The potential military and defense related applications of this technology are highlighted.

We report our recent introduction of a dynamic spectral imaging technique into a microscope system for specimen examination and classification. It uses a dynamic spectral filter and a diffraction grating on an intermediate image plane for fast spectral image acquisition that only captures interested spectral image frames. The reconfigurable capability enables the optimal spectral band selection for a specific application without hardware component modification. It can achieve 8 nm fine spectral resolution in the whole visible spectral band suitable for fluorescent image evaluation. With a fast spectral imaging update, it can support large quantify specimen screening and classification.

A dual-channel spectral imaging system with agile spectral band access and spectral bandwidth tuning capability is presented. A diffractive grating and an acousto-optic tunable filter (AOTF) are respectively used as spectral dispersion and spectral filtering elements for the two channels. A 4f spectral filtering channel using an adjustable slit is set up at the first diffraction order of the grating to realize coarse spectral band selection. The AOTF selectively filters the spectrum of the nondispersed zero order to realize fine spectral imaging. The spectral zooming function is achieved without increasing spectral frame number facilitating real-time spectral imaging operation. Feasibility of the spectral imaging has been demonstrated through preliminary experiments. Minimum 6 nm spectral resolution and 1.2 degrees field of view have been achieved. The real-time spectral imaging capable of wide spectral band operation without loosing desired fine spectral capability is particularly useful for a variety of defense, medical, and environmental monitoring applications.

In this paper, a dual-channel spectral imaging system with agile spectral band access and spectral bandwidth tuning capability is presented. A diffractive grating is used as the spectral dispersion element for the dual-channel spectral imaging system. A 4-f spectral filtering channel using an adjustable slit is set up at the first diffraction order of the grating to realize coarse spectral band selection. An acousto-optic tunable filter selectively filters the spectrum of the non-dispersed zero order to realize fine spectral imaging. The spectral zooming function is achieved without increasing spectral frame number facilitating real-time spectral imaging operation. Feasibility of the spectral imaging has been demonstrated through preliminary experiments. Minimum 6 nm spectral resolution and 1.2° field of view have been achieved. The real-time spectral imaging capable of wide spectral band operation without loosing desired fine spectral capability is particularly useful for a variety of defense, medical, and environmental monitoring applications.

In this paper, high-speed optical ribbon couplers for card-to-backplane interconnect applications are presented. The ribbon couplers are based on evanescent coupling between flexible multimode waveguide arrays. A soft lithographic technique is utilized to fabricate the ribbons. A flexible nonterminating optical data bus has been developed. Using BeamPROP software, we simulated the evanescent light coupling between two closely spaced ribbon waveguides to study the effects of waveguides separation, interaction length, and misalignment on coupling efficiency. Further experimental analysis and tests have been performed to quantify these effects. To investigate data transmission performance, a 12-channel optical interconnect link has been assembled. Experimental results demonstrated successful evanescent coupling; facilitating auto alignment coupling between card and backplane ribbon waveguides at data speeds as high as 10 Gb/s per channel. The evident high-speed interconnect performance and rapid ribbon prototyping approach can result in overall lower cost coupler fabrication for prospective optical interconnect applications.

By using a hybrid diffractive and refractive achromat with extended depth of focus, we have successfully recorded a micro-hologram array with diffraction-limited individual spot size maintained throughout the thickness of recording medium. An electrically programmable wavelength combiner was constructed in which a white light source was adopted. By modifying on a commercial CD readout head, we configured a compact micro-hologram recording/readout system that is compatible to existing disk storage technology. Base on the wavelength combiner and recording/readout system, wavelength-multiplexed micro-holograms were recorded and recovered. The presented results demonstrate the practicality of our novel storage architecture.

We report a new spectral imaging system with spectral zooming capability based on the Fourier spatial filter principle. It is suitable for real-time application. The imaging results and spectral resolution is presented.

Micro-grating multiplexing is obtained by using a single beam containing multiple wavelengths from white light coded with a wavelength combiner. In addition, we have successfully recorded micro-grating array with diffraction-limited pit size.