Abstract: A semiconductor laser includes an active region designed as a DFB laser and a passive resonator section that is optically coupled to the active region. The active region has a first section with a Bragg grating and a second section with a second Bragg grating that differs from the first Bragg grating. The two Bragg gratings differ from one another such that one and only one main mode of a DFB mode spectrum of the first section overlaps with one of two main modes of a DFB mode spectrum of the second section.

Abstract: A method for producing pistons that can be used in internal combustion engines made from lightweight metal, with a combustion bowl assigned to one piston head, wherein a bowl rim is subjected to a melt treatment. In a first method step, the bowl rim is inductively heated. In a second method step, the material of the bowl rim, also to be referred to as the delimiting zone, is improved by means of a laser beam.

Abstract: An inexpensive and compact arrangement for the electrical control and fast modulation of THz transmitters and THz measuring systems is proposed, wherein said arrangement is stable, requires no mechanical movements and operates with a purely electric control, consumes little power and also has a high speed potential for the phase modulation. This is achieved by replacing the components known from the state of the art, namely two lasers, the beam splitters, the couplers and the mechanically moved delay line, with a compact monolithic or hybrid integrated chip (10), particularly a so-called optical master chip without moving parts that comprises at least the two lasers (1, 2), the beam splitters (S3.1, S3.2), the couplers (K3.1, K3.2) and a phase modulator (4.1) for one of the laser waves such that the two generated beat signals are respectively delivered to different chip outputs (6, 7) in order to separately control the THz transmitter and the local oscillator.

Abstract: An all-optical clock recovery system for recovering the clock from a received optical signal with a short response time and without patterning effects includes a first optical clock recovery device adapted to supply a first optical clock signal in response to the received optical signal and a second optical clock recovery device adapted to supply a second optical clock signal in response to the first optical clock signal. Applications include regenerating optical packets in asynchronous optical packet-switched telecommunication networks.

Abstract: The invention relates to a wavelength-maintaining purely optical signal regenerator to which degraded optical signals with a high data rate are transmitted and regenerated without opto-electronic or wavelength conversion using compact, non-linear semiconductor components with low power consumption.

Abstract: [The aim of the invention is to realize both 3R regeneration as well as an adjustable wavelength conversion with one component. The 3R regenerator should be constructed with components that are less technically complex than those of the prior art. In a] A 3R regenerator which is provided with wavelength conversion and which comprises means for generating clock pulses, a non-linear discriminator, and means for generating and/or adjusting the output wavelength, [the invention provides that] the means for generating and/or adjusting the output wavelength [is] being a laser. [This laser, in addition to the means for generating clock pulses to the discriminator, is constantly operated, is connected to the discriminator, and its light having the desired wavelength is beamed into the discriminator. A delay line is located between the means for generating clock pulses and the discriminator.

Abstract: Optical device (1) for the differentiation of a first optical signal and an optical signal lagging behind the first, in which the differentiation is represented by a signal carried by a continuous wave passing through the two arms (5, 6) of an interferometer comprising media with an index that depends on the optical power passing through them. The delayed signal is the first signal fed back to one of the arms through a delay (7).

Abstract: An optical device for the differentiation of a first optical signal and an optical signal lagging behind the first, in which the differentiation is represented by a signal carried by a continuous wave passing through the two arms of an interferometer including media with an index that depends on the optical power passing through them. The delayed signal is the first signal fed back to one of the arms through a delay.

Abstract: An all-optical clock recovery system for recovering the clock from a received optical signal with a short response time and without patterning effects includes a first optical clock recovery device adapted to supply a first optical clock signal in response to the received optical signal and a second optical clock recovery device adapted to supply a second optical clock signal in response to the first optical clock signal. Applications include regenerating optical packets in asynchronous optical packet-switched telecommunication networks.

Abstract: A Q-switched semiconductor laser is supposed to facilitate high-frequency laser modulation with low currents or voltage ranges. According to the invention, a laser of this type consists of at least one continually pumped active medium and two optically coupled resonators at least one of which is passive, both resonators having different mode combs corresponding to the Nonius principle, at least one resonator mirror taking the form of a reflector with strongly dispersive reflection characteristics in the laser wavelength range selected by the double resonator, the index of refraction of the passive resonator and/or reflector capable of being adjusted electronically.

Abstract: In a self-pulsing multi-section laser having two DFB sections, a Fabry-Perot-like resonator formed from two reflectors and a spacer is integrated into the multi-section laser and optically coupled to at least one DFB section. The spacer has a similar layer structure to the adjacent DFB sections (D.sub.1 and D.sub.2) but not DFB grid and takes the form of a control section operable electrically separated from the DFB sections. Selection is unnecessary. The self-pulsing two-section DFB laser of the invention with an integrated control section is suitable for optical beat regeneration in high-rate communication systems.

Abstract: A measurement method is presented for the determination of low levels of optical absorption in any material, with at least a quasi-simultaneous detection of the transmission intensities of a measurement light beam and a reference light beam, the wavelengths of which are different, such that, essentially, the measurement light is absorbed by the material to be tested, and with a joint analog acquisition of the detected measurement and reference signals, taking into consideration the natural difference in intensities between the measurement light beam and the reference light beam.