Abstract: A method and system for generating an optical frequency comb that employs a dual parallel modulator that inputs an optical signal at a center frequency of a desired optical frequency comb and an RF signal at a frequency corresponding to a desired spacing of the teeth of the optical frequency comb. The amplitudes of the teeth of the optical frequency comb are controlled by controlling the amplitudes of the two RF inputs to the DPM and the phase shift between the two RF inputs. In some embodiments, the three bias voltages for the three interferometers in the DPM are also controlled. In some embodiments, all three interferometers are all biased at the same point (e.g, quadrature). Preferably, but not necessarily, the three interferometers of the DPM are formed on a single substrate.

Abstract: Systems and methods according to the present invention address this need and others by providing SLD devices and methods for generating optical energy that reduce internal reflections without the use of an absorber region. This can be accomplished by, among other things, adapting the waveguide geometry to dump reflections from the front facet out through the back facet of the device.

Abstract: Semiconductor devices having various combinations of curved waveguides and mode transformers are described. According to some exemplary embodiments, the mode transformer itself can be fabricated as all or part of the curved waveguide. For these exemplary embodiments it can be beneficial to use mode transformers whose active regions are relatively small to minimize losses associated with the introduced curvature, e.g., mode transformers that employ resonantly coupled waveguides and a tapered active waveguide in the mode transformation region. According to other exemplary embodiments, the mode transformer can be disposed along a straight portion of the waveguide, e.g., between the curved portion of the waveguide and the back facet. The present invention also provides flexibility in manufacturing by permitting different types of devices to be generated from a wafer depending upon where the devices are cleaved.

Abstract: The present invention relates to an optical modulator including an optical waveguide, and at least one CPW-to-CPS transition. The CPW segments include a hot electrode; and a ground plane disposed on each side of the hot electrode, and they share a ground plane. The CPS segment extends along an interaction length of the modulator. In one embodiment, two driving signals are applied so that the modulator operates as a dual-drive modulator. In another embodiment, a domain-inverted region is formed in a substrate of the dual-drive modulator to overlap with one arm of the optical waveguide (MZI) and invert a sign of a phase shift induced in that arm. Finally, a fixed chirp can be introduced into the dual-drive modulator by asymmetrically positioning the interferometer arms into gaps of the CPW segments with respect to the hot electrode, and by employing unequal width gaps in the CPW segments.