Abstract:
Waveguide designs and fabrication methods provide adiabatic waveguide eigen mode conversion and can be applied to monolithic vertical integration of active and passive elements in PICs. An advantage of the designs and methods is a simple fabrication procedure with only a single etching step in combination with subsequent well-controllable selective oxidation. As a result, improved manufacturability and reliability can be achieved.
Abstract:
A semiconductor laser comprises an electrically isolated active section and at least one noise reducing section and operates on a ground state transition of a quantum dot array having inhomogeneous broadening greater than 10 nm. The laser preferably emits more than 10 optical modes such that a total relative intensity noise of each optical mode is less than 0.2% in the 0.001 GHz to 10 GHz range. The spectral power density is preferably higher than 2 mW/nm. An optical transmission system and a method of operating a quantum dot laser with low relative intensity noise of each optical mode are also disclosed.
Abstract:
An optical transmission system includes a Fabry-Perot semiconductor diode laser, a transmitter and a receiver. The laser operates in a continuous-wave regime on an inhomogeneously broadened optical transition of the active region of the laser. A spectral bandwidth of an output lasing spectrum of the laser is greater than 5nm and a spectral power density of the laser is greater than 2mW/nm such that an optical power of the laser is greater than 1OmW. The laser provides a plurality of longitudinal modes (optical signals) of the resonator at different wavelengths. A relative intensity noise of at least ten longitudinal modes does not exceed -120 dB /Hz at 0.1GHz, -130 dB /Hz at 1.0GHz and - 140 dB /Hz at 10GHz. The transmitter is capable of providing modulation to each lasing wavelength independently and the receiver is capable of providing detection to each lasing wavelength independently.
Abstract:
A transversely-coupled distributed feedback laser diode, which can be processed without overgrowth, is disclosed. The laser is made from an epitaxial heterostructure including a core layer located between two cladding layers, a cap layer, and at least one Al-rich layer. The lateral waveguide is formed by selective oxidation of the Al-rich layer. A surface corrugated grating is formed above the waveguide. The heteroepitaxial structure is designed so that the core layer is placed in close proximity to the top of the laser structure to provide a required overlap between the light and the grating. In order to avoid inadmissible optical losses, there is no metallization above the waveguide. Instead, the metal contacts are offset at some distance, so that the current has to spread in the cap layer before vertical injection into the core layer.
Abstract:
A transversely-coupled distributed feedback laser diode, which can be processed without overgrowth, is disclosed. The laser is made from an epitaxial heterostructure including a core layer located between two cladding layers, a cap layer, and at least one Al-rich layer. The lateral waveguide is formed by selective oxidation of the Al-rich layer. A surface corrugated grating is formed above the waveguide. The heteroepitaxial structure is designed so that the core layer is placed in close proximity to the top of the laser structure to provide a required overlap between the light and the grating. In order to avoid inadmissible optical losses, there is no metallization above the waveguide. Instead, the metal contacts are offset at some distance, so that the current has to spread in the cap layer before vertical injection into the core layer.