Abstract: A semiconductor ridge laser for coupling to a single-mode optical fiber has a ridge with a narrow parallel region, a diverging region, and then a wide parallel region that is adjacent to an output facet. A pump region for the laser may be less than the entire area of the ridge and have a “T” shape. Preferably, the ridge has a depth of about 350 to 550 nm and the narrow parallel region has a length of more than 0.4 times the overall length of the ridge. The wide parallel region at the output enables the laser to obtain low thermal resistance, which leads to a low operating temperature, a low power density in the laser cavity, and low astigmatism.

Abstract: The invention relates to an optical assembly for opto-electronic packages comprising an optical fibre secured on the underside of an elongated support member in optical alignment with an opto-electronic device, wherein said support member is affixed to an aligning member, which in turn is affixed, e.g., by laser welding, to a welding platform. In a preferred embodiment, the elongated support member is a planar parallelepiped. In a further preferred embodiment, the elongated support member is a parallelepiped with an axially extended slot, in which the optical fibre is secured with its longitudinal axis substantially parallel to the axially extended slot.

Abstract: A fused optical coupler comprising a polarization maintaining fiber and a standard fiber is provided. The cross-section of the said standard fiber is smaller than the cross-section of the polarization maintaining fiber in the area of fusion of the coupler. The internal forces in the coupling area are sufficiently low to provide an extinction ratio of more than 20 dB at the output of the polarization maintaining fiber.

Abstract: To produce a fiber laser (106) a double-cladding active fiber (114) doped with Yb is predisposed to receive, near a first end (114a), a UV radiation suitable to write a first Bragg grating; during the writing process, a scanned pumping radiation is fed to the first end of the active fiber in order to excite an amplified stimulated emission between the first grating and the reflecting surface of a second end (114b) of the active fiber, previously cut and cleaned, and to consequently induce a laser emission from the active fiber; the optical power of the laser emission is measured and processed to obtain the laser efficiency; when a maximum value of the efficiency is reached, the writing process is stopped; similar steps are used to write a second grating near the second end (114b) of the active fiber.

Abstract: An amplifier including a first input for a first at least two input signals having mutually distinct wavelengths, a first output for a first at least two output signals, the first at least two output signals having said mutually distinct wavelengths, a first circulator including an input port coupled to the first input, an output port coupled to the first output, and an intermediate port coupled to a first end of a selective reflection circuit, and, a second circulator including an intermediate port coupled to a second end of the selective reflection circuit, an output port coupled to a first selective splitter, and an input port coupled to a second selective splitter, wherein the first selective splitter and the second selective splitter are centered about a first selected wavelength amongst the mutually distinct wavelengths.

Abstract: A bidirectionally pumped optical amplifier (200) comprises an active fibre (201), a first WDM coupler (204) and a second WDM coupler (205), a first pump: branch (220) coupled to said first WDM coupler (204) comprising a first laser (202) and a first grating (210), for introducing pump radiation into said active fibre (201) in a first direction, a second pump branch (230) coupled to said second WDM coupler (205) comprising a second laser (203) and a second grating (212), for introducing pump radiation into said active fibre (201) in a second direction, opposite to said first direction. The second laser has an output power PF. A first pump residual, having a power Pinj, is coupled into said second pump branch (230) from the active fibre (201) and injected into said second laser (203). The first pump branch (220) further comprises an optical isolator (211) for the pump radiation. The output power of the injected laser and the injected pump power residual are such that PF/Pinj>2.

Abstract: An optical amplifying unit includes an input for the input optical signals and an output for the output of the optical signals. A single-mode active fiber codoped with Er and Yb is optically connected to the input and the output and adapted to amplify the optical signals. A first pump source generates a first pump radiation including an excitation wavelength for Er, and a second pump source for generates a second pump radiation including an excitation wavelength for Yb. A first optical coupler optically couples the first pump radiation into the core of the active fiber in a co-propagating direction with respect to signal direction, and a second optical coupler optically couples the second pump radiation into the core of the active fiber in a counter-propagating direction with respect to signal direction.

Abstract: An optical amplifying unit (100; 100′) for amplifying optical signals in an optical transmission system has an amplification wavelength band with a lower wavelength limit greater than 1570 nm and includes an input (101) for the input of optical signals, an output (102) for the output of optical signals and an optical amplifier (104) interposed between the input (101) and the output (102) to amplify the optical signals. The optical amplifier (104) includes an amplification fiber (108) co-doped with erbium and ytterbium, at least a pump source (109, 110) to generate pump radiation and at least an optical coupler (111, 112) optically coupling the pump sources (109, 110) to the amplification fiber (108). The optical amplifying unit has a power gain of at least 31 dB when the optical signals have an input power of at least −10.5 dBm and wavelengths within the amplification wavelength band.

Abstract: An optical device comprises an input for an input optical impulse and an optical beam splitting element for supplying, from the input optical impulse, a first pair and a second pair of optical impulses. Also included is a first optical delay element to delay, by a predetermined time, at least one of the first pair of optical impulses and a second optical delay element to delay, by a predetermined time, at least one of the second pair of optical impulses. A first optical processing element supplies a first output optical signal to a first output when commanded by the first pair of optical impulses and a second optical processing element supplies a second output optical signal to a second output when commanded by the second pair of optical impulses.

Abstract: An optical transmission system includes an optical transmitting unit (10) to transmit optical signals in a transmission wavelength band above 1570 nm; an optical receiving unit to receive the optical signals; an optical fiber link optically coupling the transmitting unit to the receiving unit, at least an optical amplifying unit (100) coupled along the link and adapted to amplify the optical signals; the optical amplifying unit (100) having an amplification wavelength band including the transmission wavelength band and comprising: an input (101) for the input of the optical signals, an output (102) for the output of the optical signals, at least an erbium-doped active fiber (103a, 103b) for the amplification of the optical signals, having a first end optically coupled to the input (101) and a second end optically coupled to the output (102), a pump source (104, 106) for generating a pump radiation having a wavelength greater than 1400 nm and lower than 1470 nm, and an optical coupler (105, 107) optically coup

Abstract: A method for adding at least one added signal to, and dropping at least one dropped signal from at least one of a first transmission path and a second transmission path, the method including (i) creating a first series of signals and a second series of signals, the signals having distinct wavelengths, the first series and the second series being mutually staggered in wavelength, (ii) transmitting the first series to the first transmission path and the second series to the second transmission path, and, (iii) providing a wavelength selective switch along at least one of the first transmission path and the second transmission path, the wavelength selective switch for adding the at least one added signal and dropping the at least one dropped signal.

Abstract: An optical window signal generator which begins generation of an optical output signal in response to an optical activation pulse, and terminates generation of the optical output signal in response to an optical deactivation pulse. The rise time of the optical output signal is equal to the rise time of the optical activation pulse, and its fall time is equal to the rise time of the optical deactivation pulse.

Abstract: Device for adding/dropping optical signals into/from an optical transmission path, including input means for at least two optical signals with distinct wavelengths, comprising spectral selection means for sending at least a first signal to a first optical path and at least a second signal to a second optical path, at least a wavelength selective switching means along at least one of said first and second optical paths, for adding and dropping at least one optical signal having a predetermined wavelength selected from the optical signal wavelengths.

Abstract: An optical amplifier having a first input for inputting first optical signals propagating in a first direction having a first series of mutually distinct wavelengths; a first output for outputting second optical signals propagating in a first direction having the first series of mutually distinct wavelengths; a first amplifier for amplifying the first optical signals; a first optical circulator having an input port coupled to the first amplifier, an intermediate port coupled to a first end of a first selective reflection circuit, and an output port coupled to the first output; and a second optical circulator having an intermediate port coupled to a second end of the first reflection circuit, an output port coupled to a first selective splitter, and an input port coupled to a second selective splitter, where the input and output ports have passbands centered around a first predetermined wavelength of the first series.

Abstract: A double-passage acousto-optical device including an acousto-optical switch having a first polarization conversion region connected between first input and output ports, and a second conversion region connected between second input and output ports; and an optical combination connected between the first output port and the second input port via optical fibers and including an optical isolating element. The double-passage acousto-optical device may alternately include an acousto-optical switch including a single polarization conversion region connected between first input and output ports and also connected between second input and output ports. A bandpass filter, a notch filter, and add/drop and a tunable laser generator may be formed using the acousto-optical device.

Abstract: The invention relates to an optical amplifier, in particular for optical fiber telecommunication lines (1), operating with a transmission signal in a predetermined wavelength range, which amplifier comprises a fluorescent active optical fiber (6) doped with erbium, having two cores (11 and 12, 101 and 102), one (11, 101) of which is connected to a fiber (4) in which a transmission signal to be amplified and a luminous pumping energy are multiplexed, and to an outgoing fiber adapted to transmit the amplified signal, whereas the second core (12, 102) is optically coupled to the first core and is capable of absorbing the spontaneous erbium emission which would constitute a noise source, allowing a signal to be amplified in a wavelength range substantially corresponding to the tolerance range of the commercially available signal laser emitters.