We analyze the bifurcation mechanism responsible for the experimentally observed polarization selfmodulation ~PSM! in a vertical-cavity surface-emitting laser subject to optical feedback. We show that closed branches of time-periodic intensity solutions connecting distinct external-cavity modes ~ECMs! exhibit PSM. Along these bridges, the linearly polarized components of the optical field oscil...

Stable, narrow-linewidth optical sources are necessary in modern atomic physics. An appealing approach to achieving approximately 10 kHz frequency stability is optical feedback. We have designed a compact external cavity diode laser with optical feedback to a filter cavity mounted on a single baseplate and enclosed inside a vacuum sealed box. The design was implemented for three wavelengths add...

Sound can be described as the propagation of pressure variations in compressible media that involves compression and expansion and induces a change in the density of the medium. This change in acoustic pressure as it induces a change of the refractive index can be measured by optical methods, the most recent being the optical feedback interferometry. With this technique, a laser diode is beamin...

Optical tweezers are a powerful tool for micromanipulation and measurement of picoNewton sized forces. However, conventional interfaces present difficulties as the user cannot feel the forces involved. We present an interface to optical tweezers, based around a low-cost commercial force feedback device. The different dynamics of the micro-world make intuitive force feedback a challenge. We prop...

Optical-processor architectures for various forms of the alternating-projection neural network are considered. Required iteration is performed by passive optical feedback. No electronics or slow optics (e.g., phase conjugators) are used in the feedback path. The processor can be taught a new training vector by viewing it only once. If the desired outputs are trained to be either +/-1, then the ...

In this work we investigate the impact of the receiving end-system performance on data transfer to it via a dedicated optical circuit. Such a situation commonly exists in an e-Science application which may receive data from an optical circuit and process it simultaneously. We illustrate an end-system performance monitoring tool which can deliver the feedback of the receiving end-system performa...

In this paper we present experimental results that investigate the integration of two disparate sensing modalities, force and vision, for sensor-based microassembly. By integrating these sensing modes, we are able to provide feedback in a task-oriented frame of reference over a broad range of motion with an extremely high precision. An optical microscope is used to provide visual feedback down ...

We investigate numerically the effects of optical feedback on the intensity noise of vertical-cavity surfaceemitting lasers (VCSEL’s) under single-mode and two-mode operations. Our model includes transverse effects such as carrier diffusion and spatial hole-burning. Results indicate that the relative-intensity noise is relatively unaffected at low feedback levels except for a narrowing and enha...

While computer-based interactive learning environments can provide authentic and supportive settings for problem-based learning, they are very difficult to build. The traditional development model requires significant upfront development and results in systems that are hard to deploy and customize. In this article, we describe a feedback-driven authoring model that aims to reduce the developmen...

This paper presents a new method to improve the GBW (gain-bandwidth product) on negative feedback amplifiers. The proposed method is based on the introduction of time delay elements in the feedback loop, which can be exploited to retrieve significant bandwidth enhancements. This delayed feedback concept is analyzed, and considerations are presented for first order amplifiers, based on theoretic...