Sensors detecting angle of incoming light incidence, are basic elements of systems indicating direction to source of emission and Laser Warning Systems (LWS). Onboard satellites, sensors of such type are used to determine sun position. Another sensors are used in military systems. Current method of arrival angle estimations mostly rely on the analysis of slit projection on photosensitive array or quadrant detector. Novel solution in this paper is proposed. It is based on five detectors distributed on side walls of truncated pyramid. Such geometrical configuration of detectors allows to measure in wide field of view with good accuracy offered by a small size of active surface. The proposed algorithm is able to calculate angle of both azimuth and elevation of incoming light. Laboratory tests have also been discussed in the paper.
We developed unconventional laser scanner, which monitors the area with two independent laser beams shaped into lines. These lines are oriented perpendicular to each other. The solution is based on pulsed laser diodes and PIN photodetectors, making the whole platform more compact, lighter and cheaper comparing to the existing alternatives, which most often include an extensive high-resolution video track integrated with a scanning platform of considerable dimensions. The paper discusses the scanning methodology and presents a range analysis in the context of commercially available semiconductor lasers with the desired emission parameters. Another problem discussed in the paper is a method of forming a multimode laser beam into the shape of possibly narrow and homogenous line of light. The first issue can be settled through the application of commercially available aspherical components, while achieving perfect homogeneity requires the design and implementation of a dedicated freeform optical element. The current version of the experimental model is limited to off-the-shelf optical components, while the study also presents the design and simulation of the freeform transmitter.
We discuss the optical configuration and present mathematical modelling of intense electric fields sensor. The device is dedicated for the measurements of high power electromagnetic pulses (HPM) magnitude. For this reason, the sensor head has been designed as all-dielectric component, in order to avoid interferences with the measured fields. The laser source and detector unit are joined with the head through long optical fibres and the whole system utilizes 1.5 μm telecomm fibre technology. The sensor operation is based on Pockels effect induced by electric component of EM wave in bulk LiNbO3 crystal. Collimated laser beam propagating through the crystal is obtained by the application of miniature GRIN lens attached to the end of the fibre. Similarly, the fibre coupling of the beam after it crosses the crystal, is obtained. In the paper the focus is also put on mathematical foundations of full 3-dimentional sensing of E-field, which would enable to measure not only the magnitude, but also to determine the direction to the HPM source.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.