The dynamics of a sinusoidally driven pendulum in a repulsive magnetic field is investigated theoretically and experimentally. The experimental data are acquired using a shaft encoder interfaced to a PC which measures the angular displacement of the pendulum as a function of time. Both the theoretical simulations and the experimental measurements exhibit regions of periodic and chaotic behavior, depending on the system parameters. Amplitude jumps, hysteresis, and bistable states are also observed. The simplicity of the apparatus makes this experiment suitable for an advanced undergraduate laboratory.

A novel optical switching technique based on two symmetrically coupled semiconductor optical amplifiers operating in reverse‐bias mode is proposed and experimentally demonstrated. The device produces both noninverted and inverted hysteresis behavior with switching speed in MHz range. However, switch performance can be improved by implementing this technique in a photonic integrated circuit. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2753–2759, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25594

We experimentally demonstrate optical switching in a Fabry-Perot saturable absorber using a pump-probe technique. The saturable absorbers are multiple quantum wells, 35 and 42 pairs of alternating layers of 7 nm thick compressively strained Ga 0.42 In 0.58 AsP. These quantum wells are separated by 8 nm thick InP barriers. The reflectivity of these samples as a function of the input optical power is theoretically and experimentally investigated. A switching rate of better than 20 MHz is observed. This optical switching is based on the mechanism of controlling the reflectivity of the Fabry-Perot saturable absorber, while operating at its resonant wavelength, by the pump power. Optical switching speed of 10 ns is possible.

In this paper we discuss the implementation of a project oriented laboratory course in optics education. Through our discussion we show the relevance and necessity for such a course. The course is tailored not only to make the students to learn concepts, but to build a product from scratch to completion. Emphasis is also made on the design, performance, marketing and aesthetics of the product.

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