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Contribution: A hybrid approach involving reduced lecture content with project-based learning (PBL) was introduced to a standalone course in optics at an engineering school not specialized in this area, with promising results. Background: At most schools, optics is an elective “niche” area involving a single senior course. This presents challenges, since the topic has breadth and depth, leaving little time for application projects. Yet, seniors want future applicability. After many years, the instructor questioned his “broad-brush” approach involving many topics with limited application, especially given the role of optics and photonics in technology leadership. A literature search uncovered recent use of project-based methods for optics in K–12 and community colleges but little use in U.S. universities, suggesting an opportunity. Intended Outcomes: The authors intended that achievement and valuation by students would be greater with authentic projects and less content. Application Design: Therefore, an approach that concentrated content and project work on light’s dualistic nature in a mathematically rigorous manner was taken. With reduced content, class time was available for PBL, whereby the problem motivated the content. For light’s wave nature, five lecture weeks were followed by a project simulating the propagation of light. For the particle nature, a circuit design project to implement analog electronic circuits during class occurred after five lecture weeks. Findings: Student interviews and instructor perspectives on impacts of learning, career preparation, graduate school interest, and in-class engagement uncovered encouraging results. A direct assessment showed significantly higher homework scores with the course changes. [ABSTRACT FROM AUTHOR]

Zero-intermediate frequency (IF) receiver features the advantages of compact structure and agile operating frequency, but faces the problems of local oscillator (LO) leakage, direct current (dc) offset, even-order distortion, and in-phase/quadrature (I/Q) imbalance. In this paper, a photonic microwave I/Q mixer for zero-IF receiver is proposed based on a single integrated polarization multiplexing Mach–Zehnder modulator (PDM-MZM). Thanks to its all-optical operation and LO power optimization, an I/Q phase imbalance below 0.9°, an isolation ratio below −30 dB, and a typical conversion gain of −2.3 dB are achieved over an ultra-wide operating frequency from 10 to 40 GHz. Combined with the balanced detection techniques, the dc offset and even-order distortions are well suppressed, and the typical third-order spurious free dynamic range is 107.9 dB $\cdot $ Hz ^{2/3} . Using the proposed photonic I/Q mixer, the vector signals with various modulation formats, carrier frequencies, and data rates (200–700 Mb/s) are directly demodulated to I/Q basebands, and the error vector magnitude and the bit rate error are measured with the power range from −25 to 15 dBm. Subharmonic vector I/Q demodulation is also experimentally demonstrated. The proposed all-optical, ultra-wideband and high-efficient microwave I/Q mixer is suitable for a zero-IF receiver and may find potential applications in electronic systems such as wideband wireless communications, frequency-hopping radar, or multiband satellite transponder. [ABSTRACT FROM PUBLISHER]

The performance of mid-infrared Er3+-doped fiber lasers has dramatically improved in the last few years. In this paper, we present a numerical model that provides valuable insight into the dynamics of a dual-wavelength pumped fiber laser that can operate on the 3.5- and 2.8- \mu \textm bands. This model is a much needed tool for optimizing and understanding the performance of these laser systems. Comparisons between simulation and experimental results for three different systems are presented. [ABSTRACT FROM PUBLISHER]

We recently demonstrated orders of magnitude enhancement of two-photon absorption (2PA) in direct gap semiconductors due to intermediate state resonance enhancement for photons of very different energies. It can be expected that further enhancement of nondegenerate 2PA will be observed in quantum wells (QWs), since the intraband matrix elements do not vanish near the band center, as they do in the bulk, and the density of states in QWs is larger near the band edge. Here, we present a perturbation-theory-based theoretical description of nondegenerate 2PA in semiconductor QWs, where both the frequency and the polarization of two incident waves can vary independently. Analytical expressions for all possible permutations of frequencies and polarizations have been obtained, and the results are compared with the degenerate 2PA in QWs along with the degenerate 2PA and the nondegenerate 2PA in bulk semiconductors. We show that using QWs in place of bulk semiconductors with both the beams in the transverse magnetic-polarized mode leads to an additional order of magnitude increase in the nondegenerate 2PA. Explicit calculations for GaAs QWs are presented. [ABSTRACT FROM AUTHOR]

We present time-resolved laser-induced breakdown spectroscopy (LIBS) spectra of atomic (In I) and ionic (In II) indium lines recorded in time ranges from 500 ns to \(20~\mu \) s. Optical spectra have been acquired using a streak camera. Since it is assumed that the available supply of indium will slowly but inevitably diminish, the recycling of indium and finding the new natural sources are more and more important as the price of indium rises. The study of indium lines showed in this paper could be useful for making the LIBS detecting devices less expensive and more portable. [ABSTRACT FROM PUBLISHER]

A correction to the article "Toward Photon-Efficient Key Distribution over Optical Channels" published in the August 2014 is presented.