We used the combination of multiphoton autofluorescence (MAF), forward second-harmonic generation (FWSHG), and backward second-harmonic generation (BWSHG) imaging for the qualitative and quantitative characterization of thermal damage of ex vivo bovine cornea. We attempt to characterize the structural alterations by qualitative MAF, FWSHG, and BWSHG imaging in the temperature range of 37 to 90 degrees C. In addition to measuring the absolute changes in the three types of signals at the stromal surface, we also performed image correlation analysis between FWSHG and BWSHG and demonstrate that with increasing thermal damage, image correlation between FWSHG and BWSHG significantly increases. Our results show that while MAF and BWSHG intensities may be used as preliminary indicators of the extent of corneal thermal damage, the most sensitive measures are provided by the decay in FWSHG intensity and the convergence of FWSHG and BWSHG images.

A loaded wideband tapered slot antenna (TSA) with broad beamwidth and enhanced front‐to‐back ratio (FBR) is proposed. The antenna is obtained by adding a series of loading structures to a traditional microstrip‐fed linearly TSA (LTSA). The performance of the antenna with different loading structures has been discussed. Finally, the antenna is manufactured and measured. The measured results show good performance of impendence bandwidth is approximately 82.2% (4.3–10.3 GHz) for VSWR ≤ 2, while a pattern bandwidth of 50.4% (4.3–7.2 GHz) for more than 100° 3‐dB beamwidth (HPBW) both in E‐plane and H‐plane is obtained. Moreover, a new method for FBR improvement is presented and a moderately high average FBR (AFBR) about 19 dB is obtained in the pattern band. The simulated results agree with the measured results. All above indicates that the proposed antenna cannot only be used in wireless communication, but also as antenna unit of wide‐scan phased array antennas (WSPAAs).

Using multiphoton autofluorescence (MAF) and second harmonic generation (SHG) microscopy, we investigate the morphology and the structure of the corneal epithelium and stroma collagen of bovine cornea following injection of Pseudomonas aeruginosa. We found that corneal epithelial cells are damaged and stromal collagen becoming increasingly autofluorescent with time. We also characterized infected cornea cultured for 0, 6, 12, and 24 h by quantitative ratiometric MAF to SHG index (MAFSI) analysis. MAFSI results show that the destruction of the stromal collagen corresponds to a decrease in SHG intensity and increase of MAF signal with time.

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