Abstract: The general field of the invention is that of display systems comprising means for generating graphic symbols and an associated semitransparent display device. The display device according to the invention has two overlaid semitransparent flat display screens, one passive and the other active, each symbol displayed on the semitransparent display device comprising a first representation and a second representation. The first representation is displayed on the first display screen with a low transmission rate for the light and with a predetermined first size. The second representation is displayed on the second display screen in the same place as the first representation, with a luminance and a predetermined second size that is smaller than the first size so that the second representation is overlaid on the first representation and the displayed symbol appears bright with a dark border.

Abstract: The general field of the invention is that of display systems comprising an electronic calculator containing first image generation means and an associated semi-transparent display device, said display device intended to be arranged in front of an outside landscape. The display device according to the invention consists of two overlaid semi-transparent flat display screens, a photo-sensitive sensor and a position detection system. The first display screen is passive, its transmission rate being controlled by the first image generation means, the second display screen is active, its light emission being controlled by the first image generation means. The image generated is displayed either on the first display screen, or on the second display screen as a function of the outside landscape luminance information output by the photo-sensitive sensor and the position detection.

Abstract: The general field of the invention is that of display systems comprising an electronic calculator containing first image generation means and an associated semi-transparent display device, said display device intended to be arranged in front of an outside landscape. The display device according to the invention consists of two overlaid semi-transparent flat display screens, a photo-sensitive sensor and a position detection system. The first display screen is passive, its transmission rate being controlled by the first image generation means, the second display screen is active, its light emission being controlled by the first image generation means. The image generated is displayed either on the first display screen, or on the second display screen as a function of the outside landscape luminance information output by the photo-sensitive sensor and the position detection.

Abstract: The general field of the invention is that of display systems comprising means for generating graphic symbols and an associated semitransparent display device. The display device according to the invention has two overlaid semitransparent flat display screens, one passive and the other active, each symbol displayed on the semitransparent display device comprising a first representation and a second representation. The first representation is displayed on the first display screen with a low transmission rate for the light and with a predetermined first size. The second representation is displayed on the second display screen in the same place as the first representation, with a luminance and a predetermined second size that is smaller than the first size so that the second representation is overlaid on the first representation and the displayed symbol appears bright with a dark border.

Abstract: An optical amplifier assembly for submarine applications. The optical amplifier assembly comprises: a first and a second double stage fibre amplifier with respective first and second fibre amplifiers for amplifying optical signals (OS, OS') each propagated on a respective optical fibre, said optical fibres being operated in opposite operating directions (W-E, E-W), and a common pump source comprising a plurality of pump light sources, the common pump source being coupled via a coupler as a co-propagating pump to the first and second fibre amplifiers of the first and second double stage fibre amplifiers. The proposed optical amplifier assembly further comprises a gain flattening filter between the two fibre amplifiers of the first and second double stage fibre amplifiers. Thus the proposed optical amplifier assembly presents an increased efficiency with respect to an output power at a constant pump power and allows to adjust the pump power for maintaining a given output power without excessive NF degradation.

Abstract: An optical wavelength division multiplex transmission system (1) for transmitting optical signals (S) on a plurality of wavelength channels has a transmitting terminal (2) and a receiving terminal (3) interconnected by a transmission line (5) with at least one, preferably a plurality of optical amplifiers (4). Each of the optical amplifiers (4) comprises a Raman amplifier (6) with at least one pump light source (8.1-8.3) for pumping the transmission line (5) upstream the optical amplifier (4). It is proposed that each optical amplifier (4) comprises a single tap coupler (11) arranged downstream of the Raman amplifier (6). Optical receiving and transmitting means (14, 15) may be connected to the transmission line (5) via the tap coupler (11) for communication of data (TX, Di) between at least the transmitting terminal (2) and the optical amplifiers (4) on an optical supervisory channel (OSC) with a given wavelength.

Abstract: A demodulator for a DPSK-modulated optical signal of bit frequency 1/T, comprises an interferometric structure (3) having an input port (1) for receiving the DPSK-modulated optical signal, an output port (8), and first and second arms (4, 5) extending from said input port (1) to said output port (8), adjustment means (5, 7, 14, 16) for fine tuning a propagation delay difference of said two arms (4, 5) in a range comprising T, an optical/electrical converter (10) connected to the output port (8) of the interferometric structure (3), and a bandpass filter (12) connected to an output of the optical/electrical converter (10), the passband of which does not include 1/T. The adjustment means (5, 7, 14, 16) is adapted to tune the propagation delay according to the output power level of the bandpass filter (12).