This paper presents the multimode passive optical network for LAN (Local Area Network) application. These networks
should be cheaper and more usable than single-mode structures. The paper presents possibilities of commercial
application of multimode passive networks.
In this paper, an analysis of the construction of symmetrical and asymmetrical passive fiber optic structures is presented, as well as an analysis of the possibilities of using a collision detection method in these structures and the possibilities of transmitting optical signals through structures of this type.
In the paper we present the prototype of a straightness measuring device that uses a frequency stabilized Zeeman He-Ne laser. The He-Ne laser line is split by Zeeman effect into two circularly polarized laser beams. The frequency of the radiations differ of 1,2 MHz. The surface stabilized ferroelectric liquid crystal cell is used to stabilize the laser frequency. As the result of the laser frequency stabilization the power of both radiation is equal. The circular polarizations of two laser beams are converted into two linear polarizations perpendicular to each other. The two laser beams pass close to the measured axis. Along the axis the analyzing probe is moved. The analyzing probe changes the ratio of the power of the horizontal to the vertical polarization. This ratio is analyzed by the receiver composed of the ferroelectric liquid crystal switcher, the polarizer and the detector. The straightness of 2 m long optical bench was measured with this techniques. The resolution of 0,1 μm and the accuracy of 0.5 μm were obtained. The accuracy of presented technique is not so good as in the methods using laser interferometer but is comparable with methods using PSD, quadrant detectors or CCD at the same time offering bigger resolution.
In the report the arrangements of laser interferometers for machine history are presented; the laser interferometer LSP30 for investigation of geometry of machine tools, the setup for inspection of ball screw and laser liner for CNC machine. Outstanding feature of the interferometers is the stabilization system of laser frequency using surface stabilized ferroelectric liquid cells (SSFLC).
In this paper we are presenting the prototype of laser measuring system -- namely laser liner -- for Computer Numerical Control (CNC} machine tools and for Coordinate Measuring Machines (CMM). The laser liner is an innovatory arrangement of one frequency interferometer. The two-mode HeNe laser is used as a source of radiation whereas the surface stabilized ferroelectric liquid crystal cell (SSFLCC) for stabilization of the laser frequency. Small dimensions of the arrangements facilitate mounting of the interferometer on machine tools. Worked out advanced correction procedure of length of light wave compensates in real time the influence of parameters of atmosphere on the length of laser radiation. Another possible thing is compensation of thermal expansion of a material.