Abstract: A broadband semiconductor optical amplifier (SOA) device includes at least two gain-clamped SOAs having different spectral responses. The gain-clamped SOAs are coupled so that the broadband SOA device has a spectral response which is not attainable by any one of the gain-clamped SOAs. The gain-clamped SOAs may be coupled in different ways. For example, they may be coupled in parallel, in series, or in another different and/or more complex ways. In one implementation, the gain-clamped SOAs are vertically lasing semiconductor optical amplifiers.

Abstract: A highly heat conductive layer is combined with or placed in the vicinity of the optical waveguide region of active semiconductor components. The thermally conductive layer enhances the conduction of heat away from the active region, which is where the heat is generated in active semiconductor components. This layer is placed so close to the optical region that it must also function as a waveguide and causes the active region to be nearly the same temperature as the ambient or heat sink. However, the semiconductor material itself should be as temperature insensitive as possible and therefore the invention combines a highly thermally conductive dielectric layer with improved semiconductor materials to achieve an overall package that offers improved thermal performance. The highly thermally conductive layer serves two basic functions. First, it provides a lower index material than the semiconductor device so that certain kinds of optical waveguides may be formed, e.g., a ridge waveguide.

Abstract: A low-noise optical amplifier solves crosstalk problems in optical amplifiers by using an optical cavity oriented off-axis (e.g. perpendicular) to the direction of a signal amplified by the gain medium of the optical amplifier. Several devices are used to suppress parasitic lasing of these types of structures. The parasitic lasing causes the gain of these structures to be practically unusable. The lasing cavity is operated above threshold and the gain of the laser is clamped to overcome the losses of the cavity. Any increase in pumping causes the lasing power to increase. The clamping action of the gain greatly reduces crosstalk due to gain saturation for the amplified signal beam. It also reduces other nonlinearities associated with the gain medium such as four-wave mixing induced crosstalk. This clamping action can occur for a bandwidth defined by the speed of the laser cavity. The lasing field also reduces the response time of the gain medium.