Robert Magnusson, Ph.D.

Transcription

1 Robert Magnusson, Ph.D. Texas Instruments Distinguished University Chair in Nanoelectronics Director of the Nanophotonics Device Group Co-founder and Chief Technical Officer of Resonant Sensors Incorporated

2 Dispersion Engineering Using Leaky-Mode Resonant Photonic Lattices NSF: $330K (4 years) Proposed devices are unexploited in slow-light engineering Fabrication is particularly challenging Conduct theoretical and experimental research on dispersion properties of nanostructured resonance elements Design wideband bandpass leaky-mode resonance filters in bulk and waveguide format operating in telecommunications band Dispersion and delay optimization using cascaded delay elements in compact chip format Pre-fabrication analysis to establish detailed recipes and process steps and evaluate effect of fabrication errors Prototype fabrication and detailed optical characterization Found new class of dispersive optical elements founded on the phase response of resonant leaky-mode subwavelength periodic structures Results indicate potential new approach to fashion optical delay devices by proper consideration to dispersion properties of fundamental resonance effect and optimization of resonance phase and amplitude 6 Refereed publications, 4 conference proceedings 3 Ph.D. students supported Theoretical (dashed line) and experimental (red line) spectral response of the fabricated reflector for TE-polarization. (a) Zero-order reflectance. (b) Zero-order transmittance SEM images of fabricated GMR high reflector. (a) Magnification = 10,000. Image size is 12.0 mm x 8.6 mm. (b) Magnification = 30,000. Cursor measures the grating period as 984 nm.

3 MURI 3D Meta-Optics for High-Power Lasers AFOSR: $251,545 (3 years) High-precision fabrication Devices must withstand high laser power Stringent narrow-band filters Design GMR devices (filters, mirrors, polarizers) with highquality pre-specified spectral expressions (narrowband reflection, narrowband transmission, wideband high reflection, wave plates) using PSO to minimize internal field strengths Design GMR elements for polarization control Designed, fabricated, and characterized single-layer GMR polarizers patterned by holographic lithography Designed single-layer GMR high-reflectors (mirrors) working at a band of ~2μm wavelength with 3 different materials having different refractive indices (2.20 for TiO2, 3.48 for Si, 4.00 for Ge); fabrication of these GMR reflectors is underway 1 Ph.D. and 1 M.S. student, 2 Post-docs supported (a) Fabrication process of the GMR polarizer. (b) Holographic interference systems for patterning. (c) Physical dimensions for fabricated device.

4 Optimization of GMR Biosensors Resonant Sensors Inc: $15K (1.5 years) Computationally intensive problem Multiparametric numerical space with large ranges Design and optimization of the next generation of GMR sensors Fabrication and evaluation of the most promising designs Numerical quantification of detected species by backfitting to models Design and fabrication of optimal imprinted overcoated sensors 1 M.S. student, 1 Post-Doc supported Measured biolayer temporal dynamics for a 68 nm solution of calreticulin binding to anti-calreticulin in a PBS solution. We record both polarization states for the lowest waveguide modes. Refractive indices of the biolayer and background determined by backfitting the results in the figure above to a numerical model.

5 Requires high-power and narrow linewidth in same mirror element High-power laser operation Compact, cost-effective solution needed Wavelength Stabilized High-Power Diode Lasers for Alkali Atom Pumping R. Magnusson Photodigm, Inc.: $30K (10 mths) [Subcontract: MDA SBIR Phase I] Develop high-power laser diode sources utilizing the emerging technology of ultranarrow-line guided-mode resonance filter (GMRF) mirrors Design and fabricate narrow-line GMRF filters for operation at the Cs D2 (852 nm) absorption line Multiple working GMR mirrors designed, fabricated, and tested Narrow-line GMR mirrors designed, fabricated, and tested Laser operation in a gain chip at normal incidence demonstrated 1 Post-doc supported A model figure and calculated spectral response of an example GMRF operating at l=852 nm. Variations in resonance wavelength with the grating depth ( dg = 10 nm) are shown. The parameters are as follows: Thicknesses dg (grating depth) = 70 nm, d1 = 240 nm, d2 = 200 nm; refractive indices, n1= 1.46, n2= 1.98, nc = 1.00, ns = 1.50; grating period Λ = nm; filling factor (F) = 0.50; incident angle θin = 0º (normal incidence). Configuration of the RIE system with the white light source and OSA

6 REU Supplement: Dispersion Engineering Using Leaky- Mode Resonant Photonic Lattices NSF: $12K (2 years) Shortage of young engineers in nanotechnology Lack of funded research opportunities for undergraduates Lack of women and minorities in engineering New REU projects offered: o Develop new solar-cell technology based on leaky-mode resonant periodic thin films o Theoretical and experimental research on the dispersion properties of nanostructured resonance elements Several REU students trained successfully Accomplished set goals Some undergraduates have journal and conference papers to their name 3 undergraduate students supported so far REU student demonstrating the fabrication process of a nanophotonics device, under the supervision of a Post-Doc Researcher.