Research Highlights

Studying the polarization of light has been pursued for over two centuries, since Étienne Malus did the first related observations using a birefringent calcite crystal in 1808. Nowadays, most people have at least heard of “polarized sunglasses” — an 80-year-old invention. Engineering the polarization properties of guided waves in integrated photonic devices, however, has not…

Optical supercontinuum (SC) results from the synergy of several nonlinear and linear processes, all acting together. Supercontinuum generation is these days finding applications in biomedical imaging, optical metrology, spectroscopy, and sensing, to mention a few. In this regard, single-mode photonic crystal fibers with pre-engineered dispersion characteristics are currently commercially used in implementing spatially coherent ultrabright…

Since its invention in the late 16th Century, the optical microscope, has become an essential tool in modern biology, leading to numerous discoveries. Fluorescence is probably the most important optical readout mode because of its high sensitivity and specificity, compared with absorbance and reflectance. Whereas the remarkable breakthroughs based on fluorescence contrast, including the recent…

Nanocomposites, in particular inorganic-organic hybrids, allow for a wide range of combinations of phases with broad applications including solar energy harvesting, lighting, imaging, radiation sensing, lasers, magneto-optics and plasmonics. Intense research eff orts on optical nanocomposites are being motivated by the fascinating prospect that these materials can assume the optical properties of the inorganic phase…

Mid-infrared subharmonic optical parametric oscillators (OPO) produce frequency comb light with one-and-half-octave-wide instantaneous band and superior temporal coherence, suitable for real-time trace molecular detection. Optical parametric oscillators (OPOs) have long been recognized as a versatile means of producing optical output in important spectral regions unreachable by laser sources. The mid-IR (> 2.5 μm) is one…

Achromatization by Combined Volume Bragg Gratings & Surface Diffraction Gratings Over the last decades phase masks have found numerous applications including imaging, encryption, beam shaping, and mode conversion. There are two typical methods of making such masks. The first one controls the local geometrical path length by generating a contoured surface while the second method…

Nonlinear phenomena are fundamental to laser optics and photonics throughout a wide range of fields. However, these are generally neglected or intentionally avoided when considering free-space propagation of laser beams over >10 m. Ordinarily, air is considered a linear propagation medium although this is not true for sufficiently high laser intensities. Focusing laser beams to…

In recent years, the increasing penetration of flexible devices into the consumer products market has led to a surge of interest in flexible photonics, i.e., integrated optical systems fabricated on flexible polymer substrates that can be mechanically deformed without compromising their optical performance. In addition to being an essential component in consumer electronics, flexible photonics…

The generation of arbitrary optical waveforms in real time is of keen interest owing to their use in a broad range of applications, spanning secure communications, advanced radar and lidar systems, and control of complex optically induced phenomena. The ability to modify such signals at ultrafast rates would make radar systems more accurate, secure, and…

The liquid crystal display (LCD) has become ubiquitous and indispensable in our daily life. It is widely used in applications such as smart phones, pads, computer screens, TVs, and data projectors. Recently, the LCD is facing competition from the organic light emitting diode (OLED) display, especially in smart phones. LCDs advantage lie in their low…

Optical fiber communication is the backbone for the telecommunications infrastructure. Fueled by emerging bandwidth-hungry applications, the Internet traffic has sustained an exponential growth in the past and this trend is expected to continue for the foreseeable future. It is well known that the capacity of a communication channel cannot exceed the Shannon limit. In the…

Since the invention of the laser, there has been a continuous effort to increase its coherence. High temporal and spatial coherence is what makes lasers indispensable tools in many areas of research and technology ranging from spectroscopy to optical communications. Most lasers, especially those employing semiconductors as the active gain material, tend to support multiple…