| 摘要 |
The disclosed tunable (wavelength and/or focal length) laser typically is a surface emitting laser that comprises a multilayer structure that comprises the lower Bragg reflector and the active region. A layer of electro-optic material (typically liquid crystal material) is in contact with the top surface of the multilayer structure, and means are provided for applying a voltage across the layer of electro-optic material. In one exemplary embodiment, the layer is inside the laser cavity, making the laser wavelength tunable. In another exemplary embodiment the laser is a Z-laser that focuses the output radiation, with the multilayer structure comprising also the upper Bragg reflector. In this embodiment the layer of electro-optic material is outside the laser cavity, and the laser has tunable focal length. A still further embodiment is both wavelength- and focal length-tunable. Lasers according to the invention can be advantageously used in a variety of applications, e.g., in a wavelength division multiplexed and/or optically amplified optical fiber communication system. |
