The paper presents design of low-cost pyroelectric sensor based on polivinylidene fluoride (PVDF) film. The detector element is made of commercially available bioriented poled PVDF foil which thickness is 25 μm. The voltage response of this PVDF sensor to short radiation pulses is studied experimentally. Especially time parameters of the voltage detector response, frequency and temperature characteristic are investigated. Furthermore, influence of load resistance of preamplifier is considered.
An original semiconductor programmable light source has been designed and constructed. It consists of the controller module and the stabilized optical head comprising an optical feedback loop. The radiation emitted by the light source proposed can be generated in the continuous or pulse mode and its brightness can be adjustable in a wide range.
This paper presents problems related to differential measurements of the energy of pulse light sources with the use of pyroelectric sensors. Methods based on the use of differential measurements enable elimination of the background signal. An original, designed and constructed conversion system based on the differential method is described.
In this paper, a concept of an inexpensive PVDF pyroelectric radiation sensor of large aperture is described. The design details of a pyroelectric sensor based on the PVDF polymer are given. The preamplifier and conversion system of pyroelectric sensor signal are presented. Its photoresponse to short radiation pulses was investigated experimentally. Especially, influence of such parameters as frequency of optical pulses, width of pulses and temperature on the photoresponse of a given pyroelectric sensor was considered.
This paper presents an electronic circuit which can be used as a very fast electronic 'fuse' in laser diode drivers. The main causes of damage of laser diodes are either unexpected electrical transients or catastrophic facet damage occurring at optical power density exceeding 10<SUP>6</SUP> W/cm<SUP>2</SUP>. Both can be induced by electromagnetic interference in typical drivers with automatic power control. Presented scheme has a reaction time about 2 microsecond(s) , which reduces the possibility of over driving the laser diode.
Laser diode parameters are highly dependent on temperature. Therefore the problem of maintenance of semiconductor laser emission parameters at certain degree is a very relevant question. This paper present a laser diode controller prepared and constructed. It presents also an algorithm which enables to provide the values of operating current intensity in a certain temperature, in order to maintain a demanded value of output power. The experiments were conducted for various types of laser diode.