Two-dimensional optical ring resonators based on radial Bragg resonance

A Bragg-reflection-based ring resonator is proposed and analyzed. Closed-form expressions for the field and dispersion curves for radial Bragg gratings and photonic bandgap crystals are derived. The required gratings exhibit a chirped period and a varying index profile. Small bending radii and strong control over the resonator dispersion are possible by the Bragg confinement. Large free spectral range and low radiation loss are predicted theoretically

Giant Fiber Lasers: A New Paradigm for Secure Key Distribution

We propose and analyze a new concept for secure key distribution based on establishing laser oscillations between the sender and receiver. Compared to quantum mechanics based systems, our scheme allows for significantly higher key-establishing rates and longer ranges. By properly designing the laser structure, it is possible to increase the difficulty of eavesdropping almost arbitrarily, thus making our scheme an intriguing alternative and a complementary technology to quantum key-distribution systems

All-optical gates facilitated by soliton interactions in a multilayered Kerr medium

All-optical soliton logic operations, facilitated by incoherent interactions of multiple spatial solitons with nonlinear interfaces, are proposed and analyzed. A particlelike model, validated by beam propagation simulations, was developed for calculating the soliton trajectories and was employed for the analysis of the soliton-based logic gates

Optical annular resonators based on radial Bragg and photonic crystal reflectors

A ring resonator based on Bragg reflection is studied in detail. Closed form expressions for the field and dispersion curves for radial Bragg gratings and photonic crystals based resonators are derived and compared to FDTD simulations. For strong confinement, the required gratings exhibit a chirped period and a varying index profile. Small bending radii and low radiation losses are shown to be possible due to the Bragg confinement. The sensitivity of the resonator characteristics to fabrication errors is analyzed quantitatively. A mixed confinement configuration utilizing both Bragg reflection and total internal reflection is also suggested and analyzed

A classical key distribution system based on Johnson (like) noise - How secure?

We present a comprehensive analysis of the Johnson (like) noise based classical key-distribution scheme presented by Kish [1]. We suggest two passive attack strategies that enable an adversary to gain complete knowledge of the exchanged key. The first approach exploits the transient response of the voltage difference on the transmission line after the resistors are switched and the second one exploits the finite impedance of the wire connecting the two parties.Comment: Submitted to phys. lett. A minor typos correcte

Circulating spatial solitons

A class of optical spatial solitons exhibiting propagation in a closed-loop orbit in a two-dimensional plane is presented. A closed-form particlelike model is derived, indicating that the quasi-centrifugal force acting on these solitons can be balanced by an inhomogeneity in the nonlinear index of refraction. Specifically, a circular-shaped nonlinear interface is shown to facilitate stable orbital propagation of solitons that carve their own circular cavity for a wide range of nonlinearity parameters

Optimal Design and Reduced Threshold in Vertically Emitting Circular Bragg Disk Resonator Lasers

We derive a comprehensive coupled-mode theory, including resonant vertical emission effects, for the analysis of nonperiodic circular Bragg lasers. We derive the governing characteristic equation for such lasers, yielding the threshold gain level and the resonance frequency. By reducing the threshold gain and maximizing the ratio of “useful signal” to the power leakage, we find optimum conditions for vertically emitting circular Bragg microdisk lasers which indicate that low-threshold operation is possible

Low Threshold Two-Dimensional Annular Bragg Lasers

Lasing at telecommunication wavelengths from annular resonators employing radial Bragg reflectors is demonstrated at room temperature under pulsed optical pumping. Sub milliwatt pump threshold levels are observed for resonators with 0.5-1.5 wavelengths wide defects of radii 7-8 mm. The quality factors of the resonator modal fields are estimated to be on the order of a few thousands. The electromagnetic field is shown to be guided by the defect. Good agreement is found between the measured and calculated spectrum.Comment: 8 pages, 4 figure