Thomas Peschel

Optimization of bistable planar resonators operated near half the band gap

By using a modal approach that describes the optical response of a large class of nonlinear planar resonators under pulsed beam excitation we derive conditions to optimize the device with respect to different criteria. The influence of the nonlinearity is taken into account for both the cavity and the reflectors. The procedure results in simple algebraic formulas for the cavity thickness and the number of unit cells building the reflectors. The results hold likewise for microresonators of finite size and provide experimentalists with a useful tool to fabricate appropriate resonators for all optical switching operations. >

Temporal solitary waves near linear resonances

Solitary waves can exist near linear resonances where the dispersion is strong and nonparabolic. These solitary waves form a two-parameter family; the velocity and the wave number are these parameters. We derive analytical solutions for both bright and dark solitary waves and show that these solutions are characterized by a chirp proportional to the peak power. Moreover, these solitary waves may even exist on a continuous-wave background. Domains of existence and stability are explicitly given, and the influence of weak absorption on the solitary-wave dynamics is discussed.

The effect of excited leaky waves on the transient non-linear optical response of planar semiconductor resonators

The optically non-linear response of arbitrary planar semiconductor resonators (microresonators) is studied theoretically. We use a versatile approach that takes into account the finite beam width as well as pulse length of the incident light, and incorporates the non-linearity consistently. The intensity-dependent non-linearity of semiconductors is described by appropriate phenomenological models. We show that the propagation characteristic of the leaky waves excited controls the response behaviour of the resonators. Conditions for switching and optical bistability are identified. The effect of various parameters on the response is studied numerically.

Binary processing by spatially solitary wave steering in 2-D planar resonator structures

Abstract We show that solitary waves existing in nonlinear planar resonators illuminated under oblique incidence can be employed for all-optical binary processing. It is numerically demonstrated how the basic logical operations can be implemented.

Waveguide element for highly effective dispersion compensation in fiber transmission lines

We show that dispersion compensation over 70 km of a standard optical fiber at 20 Gbit/s can be achieved by using a strip waveguide configuration which consists of two dissimilar guides and is only a few centimeters long. Moreover, any required amount of third-order dispersion can also be compensated for.

Dynamics of two-dimensional high-transmission domains in non-linear planar resonators

Using the modal theory the optical response of a non-linear planar resonator illuminated by a genuine two-dimensional, pulsed beam is studied. We consider a defocusing Kerr-like non-linearity appearing well below the fundamental band-gap of direct semiconductors due to two-photon processes. Optical bistability is identified for normal incidence whereas it disappears if the angle of incidence of the input beam becomes comparable to the width of the resonance. No evidence for symmetry breaking could be found, whereas a pronounced beam shaping arises in the high-transmission state.