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It is shown here that microwave sensors can be used to monitor glucose in serum concentration with minimum detectable as well as resolution of 1 mMol $\cdot \text{L}^{{-1}}$ ($\approx 18$ mg $\,\cdot $ dL−1). The ultrasensitive detection technique relies on a split ring resonator, operating at the frequency of 1.156 GHz, as the core of the sensor where its loss is compensated to enhance the quality factor from $\sim 190$ (passive mode) to $\sim 3850$ (active mode) to enable high resolution (modified frequency detection error from ±12 kHz down to ±2.5 kHz) frequency-shift sensing. Initially, glucose concentrations of 100–1000 mMol $\,\cdot \text{L}^{{-1}}$ (1800–18000 mg $\,\cdot $ dL−1) in water were detected within 250 kHz of dynamic range (between two spectrum ends). Selectivity of the sensor to glucose is verified with respect to common interstitial fluid ingredients with biological levels. Finally, to enhance the resolution of the proposed sensor, its loss–compensation is further improved leading to increased accuracy of measuring glucose samples in a 0.9 % NaCl solution containing 10 % horse serum that closely resembles blood plasma and interstitial fluid. This allows exploration of lower concentrations in the physiological range 1–30 mMol $\,\cdot \text{L}^{{-1}}$ (18–540 mg $\,\cdot $ dL−1) with improved frequency detection error down to ±0.75 kHz for two cases of with/without serum solutions with dynamic range of 30 kHz/38 kHz. The highly accurate glucose monitoring technique could be utilized for developing noninvasive glucose sensors for biomedical applications in real–time glucose monitoring. [ABSTRACT FROM AUTHOR]

A technique for multi-band generation is investigated to simultaneously achieve phase-matching in multiple second-order nonlinear processes. By coupling a near-infrared excitation pulse into a LiNbO3 planar waveguiding platform, modal phase-matched second harmonic radiation is generated at wavelengths of 403 ± 0.6 nm and Cherenkov-emitted terahertz radiation is generated at frequencies up to ~3.5 THz. For the second harmonic generation process and the terahertz radiation generation process, the conversion efficiencies are measured as 1.5 × 10−2 %/(GW-cm−2) and 1.9 × 10−4 %/(GW-cm−2), respectively. The investigated multi-band generation technique permits a single structure to produce radiation within multiple spectral bands, such that this technique could be used to increase the density of photonic sources on a photonic integrated chip. [ABSTRACT FROM AUTHOR]

An angular coupling configuration is shown to facilitate phase-matched second harmonic generation between the TE1 fundamental and TE4 second harmonic modes of a LiNbO3 planar waveguide. For an incident coupling angle of 10°, 2.6% coupling efficiency is achieved for the TE1 waveguide mode, thus permitting visible light generation at the wavelength of 402.4 nm through phase-matching to the TE4 second harmonic mode. For a 2.8 mm-long LiNbO3 planar waveguide excited at an energy of 1.8 nJ, the second harmonic generation conversion efficiency is 4.6 × 10−5. The ability of this angular coupling scheme to facilitate phase-matched frequency-conversion makes it ideal for use in optical computing, optical communications, and quantum computing. [ABSTRACT FROM AUTHOR]

Focuses on the development of magnetooptic deflector based on thin-film iron garnet materials. Dynamics of magnetization; Polarization selectivity of deflected beam; Induction of high-frequency ferromagnetic resonance response of bismuth-substituted garnet.