Abstract: A system suitable for the amplification of wide-band signals, with frequencies from zero to the gigahertz order, for oscilloscopic observation or recording. Included are first and second amplifier circuits. The first amplifier circuit, typically of multistage configuration, has two inputs, one for the reception of a wide-band signal to be amplified and the other for the reception of a low-band signal, and puts out an amplified wide-band signal in response to the wide- and low-band input signals. Comprising an operational amplifier, the second amplifier circuit also has two inputs for the reception of the low-frequency components of the wide-band input and output signals of the first amplifier circuit and, in response to these inputs, produces the low-band signal for delivery to the mentioned other input of the first amplifier circuit.

Abstract: A combination of a circular/straight line light beam scan transforming apparatus and optical device constitutes an optical system. In the optical device, a light beam whose intensity is varied by a modulation signal is produced, and an object is exposed to the scanning beam from the light beam scan apparatus. The light beam scan apparatus includes a circular/straight line transforming optical fiber assemblage having a cylindrical portion and a linear portion. The cylindrical portion has a fore end part bent toward the center thereof so that the extension of the bent part intersects the axis of rotation of a rotary mirror rotatable at high speeds. The light beam produced in the optical device is directed to the rotary mirror and reflected thereby, focussed on the fore end part, transmitted through the optical fiber assemblage and emitted from the linear portion as a linear scanning beam in a sequence in conformity to the sequence of reception of light beam by the cylindrical portion.

Abstract: A light signal observation device, which is provided in combination with light receiving means for detecting a light signal, light intermitting means for intercepting or passing therethrough the light signal incident to the light receiving means, amplifying means for amplifying the output from the light receiving means; time base signal generating means for generating a sawtooth wave in synchronism with the light signal and also while the light signal is intercepted and for generating a luminance modulation signal in the period of generation of the sawtooth wave, and display means for displaying an optical signal waveform including a 0 level on the basis of the output signal from the amplifying means and the sawtooth signal and the luminance modulation signal from the time base signal generating means. The light signal observation device of this invention may be constructed as a synchroscope or a sampling oscilloscope.