26 research outputs found
Resonance enhancement of magnetic Faraday rotation
Magnetic Faraday rotation is widely used in optics. In natural transparent
materials, this effect is very weak. One way to enhance it is to incorporate
the magnetic material into a periodic layered structure displaying a high-Q
resonance. One problem with such magneto-optical resonators is that a
significant enhancement of Faraday rotation is inevitably accompanied by strong
ellipticity of the transmitted light. More importantly, along with the Faraday
rotation, the resonator also enhances linear birefringence and absorption
associated with the magnetic material. The latter side effect can put severe
limitations on the device performance. From this perspective, we carry out a
comparative analysis of optical microcavity and a slow wave resonator. We show
that slow wave resonator has a fundamental advantage when it comes to Faraday
rotation enhancement in lossy magnetic materials
Giant Slow Wave Resonance for Light Amplification and Lasing
We apply the idea of giant slow wave resonance associated with a degenerate
photonic band edge to gain enhancement of active media. This approach allows to
dramatically reduce the size of slow wave resonator while improving its
performance as gain enhancer for light amplification and lasing. It also allows
to reduce the lasing threshold of the slow wave optical resonator by at least
an order of magnitude.Comment: Preliminary version of the manuscrip
Optical switching performance of thermally oxidized vanadium dioxide with an integrated thin film heater
Optical switching performance of vanadium dioxide produced by thermal oxidation of vanadium is presented in this paper. A 100nm thick vanadium was oxidized under controlled conditions in a quartz tube furnace to produce approximately 200nm thick VO2. The substrate was appropriately coated on the front and back side to reduce reflection in the cold state, and an integrated thin film heater was fabricated to allow in-situ thermal cycling. Electrical measurements show a greater than three orders of magnitude change in resistivity during the phase transition. Optical measurements exhibit 70% transparency at 1500nm and about 15dB extinction across a wide spectral band between 1000nm and 3000nm. These results are used to show a huge optical bistability effect in VO2-based devices
Nonlinear Wavepacket Dynamics in Proximity to a Stationary Inflection Point
A stationary inflection point (SIP) in the Bloch dispersion relation of a
periodic waveguide is an exceptional point degeneracy where three Bloch
eigenmodes coalesce forming the so-called frozen mode with a divergent
amplitude and vanishing group velocity of its propagating component. We have
developed a theoretical framework to study the time evolution of wavepackets
centered at an SIP. Analysis of the evolution of statistical moments
distribution of linear pulses shows a strong deviation from the conventional
ballistic wavepacket dynamics in dispersive media. The presence of nonlinear
interactions dramatically changes the situation, resulting in a mostly
ballistic propagation of nonlinear wavepackets with the speed and even the
direction of propagation essentially dependent on the wavepacket amplitude.
Such a behavior is unique to nonlinear wavepackets centered at an SIP.Comment: 9 pages, 5 figure