Abstract: A transmitter and a receiver for an optical telecommunication system of the WDM type are disclosed. In one aspect, the transmitter uses a chromato-temporal encoder which, with each block of symbols to be transmitted, associates a code matrix, where each element of the matrix corresponds to a wavelength and a use of the channel. The transmitter includes multiple modulators, where each modulator modulates a laser beam at a wavelength during a use of the channel by an element corresponding to the code matrix. The beams modulated in this manner are multiplexed in an optical fiber. Another embodiment using both a wavelength and a polarization encoding is also proposed.

Abstract: A transmitter and a receiver for an optical telecommunication system of the WDM type are disclosed. In one aspect, the transmitter uses a chromato-temporal encoder which, with each block of symbols to be transmitted, associates a code matrix, where each element of the matrix corresponds to a wavelength and a use of the channel. The transmitter includes multiple modulators, where each modulator modulates a laser beam at a wavelength during a use of the channel by an element corresponding to the code matrix. The beams modulated in this manner are multiplexed in an optical fiber. Another embodiment using both a wavelength and a polarization encoding is also proposed.

Abstract: The invention relates to a semiconductor laser consisting of an active waveguide comprising an active region surrounded by a filling material and which is coupled to a distributed reflector. Said distributed reflector is made from the aforementioned filling material and is disposed along the length of the lateral sides of the active region essentially parallel to same and in the form of a structuring having a photonic band gap along the longitudinal axis of the laser. According to the invention, the structuring defines a first photonic crystal with columns forming diffracting elements, said crystal comprising a mesh having dimensions of the order of the wavelength of photons in the guided mode which circulate in the active waveguide.

Abstract: A semiconductor optical device such as a laser or semiconductor optical amplifier (SOA) based on an indium phosphide substrate or equivalent buffer layer. The active layer of the device is based on conventional InGaAs(P) alloy, but additionally includes N in order to increase the operating wavelength to greater than 1.5 ?m, preferably to a wavelength lying in the C- or L-band. The active layer composition may thus be denoted In1-xGaxAsyNzPp with x?0.48, y?1?z?p, z?0.05, p?0. The active layer may include a quantum well or multi-quantum wells in which case its thickness is preferably less than the critical thickness for lattice relaxation. In other embodiments the active layer is a “massive” layer with quasi-bulk properties. The active layer may advantageously be under tensile stress, preferably roughly between 1% and 2.2%, to manipulate the light and heavy hole bands. The active layer is typically bounded by barrier layers made of a suitable semiconductor alloy, such as AlInAs or InGaAs(P).

Abstract: The invention relates to a semiconductor laser consisting of an active waveguide (3) comprising an active region surrounded by a filling material (5) and which is coupled to a distributed reflector (7, 8). Said distributed reflector (7, 8) is made from the aforementioned filling material (5) and is disposed along the length of the lateral sides of the active region (4) essentially parallel to same and in the form of a structuring having a photonic band gap along the longitudinal axis (X) of the laser. According to the invention, the structuring defines a first photonic crystal with columns (9) forming diffracting elements, said crystal comprising a mesh having dimensions of the order of the wavelength of photons in the guided mode which circulate in the active waveguide (3).

Abstract: A semiconductor optical device such as a laser or semiconductor optical amplifier (SOA) based on an indium phosphide substrate or equivalent buffer layer. The active layer of the device is based on conventional InGaAs(P) alloy, but additionally includes N in order to increase the operating wavelength to greater than 1.5 ?m, preferably to a wavelength lying in the C- or L-band. The active layer composition may thus be denoted In1-xGaxAsyNzPp with x?0.48, y?1-z-p, z?0.05, p?0. The active layer may include a quantum well or multi-quantum wells in which case its thickness is preferably less than the critical thickness for lattice relaxation. In other embodiments the active layer is a “massive” layer with quasi-bulk properties. The active layer may advantageously be under tensile stress, preferably roughly between 1% and 2.2%, to manipulate the light and heavy hole bands. The active layer is typically bounded by barrier layers made of a suitable semiconductor alloy, such as AlInAs or InGaAs(P).