Rolf Heidemann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: A system for optically transmitting a useful signal (S.sub.1) from a transmitter (1) over a transmission link which includes either an optical waveguide (3) or a fiber-optic network coupled to a receiver (2). The transmitter (1) transmits the useful signal (S.sub.1) and an auxiliary signal (S.sub.2) over the transmission link toward the receiver (2) at different wavelengths. Circuits (4a, 4b, 5, 6, 7) at a desired point in the transmission link and analyze the auxiliary signal (S.sub.2) and provide a response signal (S.sub.3) containing information for monitoring the useful signal. The transmitter (1) receives the response signal (S.sub.3) and controls the further transmission of the useful signal (S.sub.1) and the auxiliary signal (S.sub.2) in accordance with the information in the response signal (S.sub.3).
Abstract: In an optical communication system with a fiber-optic amplifier which includes a wavelength-selective fiber-optic coupler for coupling pump light into the amplifying length of fiber, an additional optical signal, e.g., a service-channel signal, is transmitted from the location of the fiber-optic amplifier in one direction or the other by being used to modulate the pump light. Since the pump light is not completely absorbed in the amplifying length of fiber, a sufficient portion is transferred from the length of fiber into the optical waveguide of the optical communication system and passes down the optical waveguide to the end point of the communication system. There, it is coupled out and passed to an optical receiver from whose output the transmitted additional signal is recovered by demodulation.
Abstract: In a reflective optical modulator light enters through an optical waveguide into a detunable optical resonator which couples it back into the optical waveguide, the modulation being effected by detuning the resonator. The resonator includes the end face of the optical waveguide through which the light enters and is coupled back, and a first reflective surface disposed opposite this face.
Abstract: In a cellular mobile-radio system with radio stations and transmission facilities remote therefrom, the radio stations send out radio signals and receive radio signals which, in each case, contain information signals. According to the invention, as many as possible of the processing functions are shifted from the radio stations to the transmission facilities. The radio signal to be sent out by the radio station is easily generated in the radio station because in the transmission facility, an unmodulated carrier and a carrier modulated with the information signal is produced, in which case the carriers differ in frequency by the amount of the carrier frequency of the radio signal. These two optical carriers are transmitted to the radio station and are mixed there in an optical receiver, so that the radio signal containing the information signal is generated. A radio signal that is received in a radio station is transmitted optically to a the transmission facility and is processed further there.
Abstract: An optical system includes an optical amplifier having a laser active substance and a first laser that generates pump light at a first wavelength for the laser active substance, a second laser which generates light a second wavelength selected so that the light of the second wavelength can be amplified in the optical amplifiers, a first coupler for coupling the light of the second wavelength into the optical amplifier, a third laser which generates light at a third wavelength, and a second coupler for coupling light of the third wavelength into the optical amplifier. The wavelength of the light generated by the third laser is selected so that amplification of the light of the second wavelength on the basis of the pump light can be controlled as a function of the intensity of the light generated by the third laser.
Abstract: A circuit arrangement includes a signal source having a high-ohmic complex output impedance, an amplifier having a low-ohmic input impedance for receiving a signal from the signal source, and a tuned quarter wavelength circuit for matching the signal source to the amplifier.
Abstract: In an optical communication system with a fiber-optic amplifier (10) which includes a wavelength-selective fiber-optic coupler (12) for coupling pump light into the amplifying length of fiber (11), according to the invention, an additional optical signal from, e.g., a service channel is transmitted from the location of the fiber-optic amplifier (10) in one direction or the other by being coupled into the unused port (4 ) of the wavelength-selective fiber-optic coupler (12). Any coupler (12) suitable for coupling the pump light into the amplifying length of fiber (11) can thus be used to couple an additional optical signal into the fiber-optic link (15) of the system without any special step having to be taken.
Abstract: The invention is based on the problem of transmitting a frequency-division multiplex signal occupying a board frequency band, e.g., the cable television frequency band of 47-440 MHz, over an optical waveguide transmission section. According to the invention, in the transmitting unit, the whole frequency band to be transmitted is divided into two sub-bands (FB.sub.1, FB.sub.2), and the lower sub-band (FB.sub.1) is converted by means of single-sideband amplitude modulation of a high-frequency carrier (f.sub.0) into a higher-frequency transmission frequency band, e.g. 497-688 MHz, which is less than one octave in width, based on its lowest frequency. The lower sub-band (FB.sub.1) and the transmission frequency band produced by the conversion are converted separately into optical signals with different wavelengths (.lambda..sub.1, .lambda..sub.2) and are transmitted in a wavelength multiplex procedure via the optical waveguide.
Abstract: To transmit a frequency-division multiplex signal occupying a broad frequency band, e.g., the 40-440 MHz cable television frequency band, over an optical-fiber transmission link, in the transmitter, the whole frequency band to be transmitted is converted by single-side-band amplitude modulation of a high-frequency carrier f.sub.0 to a higher-frequency band, e.g., 840-1240 MHz, which, referred to its lowest frequency, is less than one octave wide. Second-order intermodulations products, which usually result during electric-to-optical conversion, thus fall into unoccupied frequency ranges. At the receiving end, corresponding demodulation is performed employing either carrier recovery or a locally generated carrier. In a preferred embodiment, the frequency band to be transmitted is converted to the higher frequency band in several subbands.
September 12, 1991
Date of Patent:
July 7, 1992
Rolf Heidemann, Heinz G. Krimmel, Berthold Wedding
Abstract: A fiber-optic amplifier, whose light signal input and light signal output may be connected with a monomode fiber for 1536 nm light signals, is composed of two or more cascade connected amplifier stages including a fiber piece that amplifies light signals and is doped with at least one lanthanoid, a wavelength selective directional coupler and a pump light source. The output end of the fiber piece of one amplifier stage, when seen in the direction of travel of the light signals, is connected with the one input of the directional coupler of the next-following amplifier stage. The fiber pieces of the individual amplifier stages are different from one another with respect to length and/or doping and/or basic material so as to realize maximum gain for different wavelengths. Such a fiber-optic amplifier offers nearly constant gain over a broad wavelength range.
Abstract: In a signal connecting device for the establishment of communication paths between insertable units in a rack in which signal connections are formed by at least one optical waveguide which is associated with a rear panel of the rack, coupling is effected by imaging lenses associated with the insertable units. When a unit is inserted, its associated lenses are disposed opposite or lie against the optical waveguide of the rear panel.
Abstract: In optical communication systems for transmitting a plurality of broadband signals, particularly television signals, over an optical waveguide, the signals are modulated onto carriers of different frequencies, and the modulated carriers are transmitted as frequency-division-multiplex signals. The carrier frequencies lie in different frequency bands (B.sub.1, B.sub.2, B.sub.3) each of which is not more than one octave wide and which are spaced at least one octave apart. This makes it possible to adapt the system step by step to channel requirements using conventional, proven transmission equipment for the individual frequency bands.
Abstract: A printing press convertible from intaglio to flexographic (letterpress) printing comprises a rubber impression cylinder and a steel impression cylinder which are selectively applied to an appropriate plate cylinder. The steel cylinder is carried by a displaceable carriage and the rubber cylinder can be swung from an operative position interposed between the steel and plate cylinders to an inoperative position above the steel cylinder by being carried by pivotable arms. A guide roller, over which the web to be printed is passed towards the plate cylinder is displaceable from a position directly above the steel cylinder during flexographic printing to a position above and at one side of the steel cylinder during intaglio printing.