Abstract:
An external resonant optical modulator is provided by forming a waveguide electrode structure coupled to a coplanar strip or coplanar waveguide pattern including a ring resonator electrode and a ground electrode substantially surrounding the ring resonator electrode. These electrode patterns are disposed on an electrooptic substrate that includes an optical waveguide pattern. The waveguide electrode structure includes an RF feed line electrode coupled to the ring electrode. The RF feed line signal excites an inherent resonant mode of the ring to thereby cause an electric field to resonate between the ring electrode and ground electrode and pass into sections of the optical waveguide pattern. By appropriately positioning the ring and ground electrodes to overlay portions of the optical waveguide structure in the electrooptic substrate, a light beam launched into the waveguide pattern can be modulated to produce a pulse with zero chirp. The resonant modulator may be used in communication systems, such as a DWDM system, and may be formed as an individual device, or cascaded in series or parallel fashion with a plurality of optical modulators and other optical devices on a common electrooptic substrate.
Abstract:
An optical modulator device that substantially prevents coupling of a desired coplanar waveguide (CPW) electromagnetic wave mode with other spurious modes within non-active sections the modulator structure without significantly impacting the modulation efficiency in an active section of the device. The modulator includes an electrooptic substrate and a buffer layer that is formed on a surface of the electrooptic substrate. The buffer layer includes a thin portion that occupies an active section of the electrooptic substrate where modulation occurs, and a thicker portion that overlies the electrooptic substrate in one or more non-active sections of the device. The thinner portion of the buffer layer allows significant electrical-optical overlap of the CPW electromagnetic wave with an optical wave propagating within a waveguide formed in the active section of the device substrate. One or more thicker buffer layer portions on one or more non-active sections of the electrooptic substrate substantially prevent penetration of the CPW electromagnetic field into the electrooptic substrate in the non-active sections, and thus restrict coupling with undesirable modes the electrooptic substrate can support.
Abstract:
An optical waveguide device including an electro-optical crystal substrate having a top surface and a bottom surface; an optical waveguide path formed within a surface of the electro-optical crystal substrate; at least one electrode positioned above the optical waveguide path for applying an electric field to the optical waveguide path; and a silicon titanium oxynitride layer and a connecting layer for interconnecting the silicon titanium oxynitride layer to another surface of the electro-optical crystal substrate that is opposite to the surface in which the optical waveguide path is formed.
Abstract:
An optical device includes a grounded base and an optical modulator chip having a top surface, a back surface and side surfaces. The optical modulator chip includes a first ground electrode, a signal electrode and a second ground electrode located over the top surface of the optical modulator chip. A resistive paint is on the back surface of the optical modulator chip to reduce losses due to extraneous modes or bias instabilities.
Abstract:
An optical device includes a grounded base and an optical modulator chip having a top surface, a back surface and side surfaces. The optical modulator chip is positioned on the grounded base with the back surface facing the grounded base. The optical modulator chip includes a first ground electrode, a signal electrode and a second ground electrode located over the top surface of the optical modulator chip. The first and second ground electrodes of the optical modulator chip are interconnected on a surface of the optical modulator chip.
Abstract:
An optical waveguide device including an electro-optical crystal substrate having a top surface and a bottom surface; an optical waveguide path formed within a surface of the electro-optical crystal substrate; at least one electrode positioned above the optical waveguide path for applying an electric field to the optical waveguide path; and a silicon titanium oxynitride layer and a connecting layer for interconnecting the silicon titanium oxynitride layer to another surface of the electro-optical crystal substrate that is opposite to the surface in which the optical waveguide path is formed.
Abstract:
A fiber tail assembly is provided that includes an outer sleeve, which can be attached and hermetically sealed to the housing of an optical device, and a sealing ferrule, which may be inserted into and hermetically sealed to the outer sleeve. An optical fiber may be inserted through an axial bore in the sealing ferrule and hermetically sealed thereto, such as with a glass seal. The hermetic seal between the sealing ferrule and the fiber avoids high or transversely asymmetric stress that may change the birefringence of the fiber. The optical fiber may be inserted through a cap ferrule or a stress relief tube, which may be attached to the fiber and to the outer sleeve, protecting the fiber tail assembly from axial stress that may damage the fiber or the hermetic seals. Methods for forming the same are provided.
Abstract:
An optical device includes a grounded base and an optical modulator chip having a top surface, a back surface and side surfaces. The optical modulator chip is positioned on the grounded base with the back surface facing the grounded base. The optical modulator chip includes a first ground electrode, a signal electrode and a second ground electrode located over the top surface of the optical modulator chip. The first and second ground electrodes of the optical modulator chip are interconnected with resistive layers on a surface of the optical modulator chip.
Abstract:
A programmable chirp optical modulator is provided having programs modes of chirp. The modulator includes an optical modulation chip substrate having an electrooptic property; a waveguide that runs across the optical modulation chip, wherein the waveguide includes a first main channel branching into separate parallel first and second waveguide arms that combine into a second main channel; a first coplanar-strip electrode overlying and running along the first waveguide arm; a second electrode overlying and running along the second waveguide arm; and at least one programmable electrode overlying the substrate and adjacent to the second electrode on a side of the second coplanar-strip electrode opposite a side of the second coplanar-strip electrode where the first coplanar-strip electrode is located. The at least one programmable electrode runs in parallel with the second electrode as the second electrode runs along the second waveguide arm.
Abstract:
A Mach-Zehnder Interferometer having a waveguide including an input portion for receiving an optical signal and having a first channel width, a first splitter for separating the optical signal into at least first and second paths, a first arm for the first path and having a second channel width that supports a single transverse optical mode, a second arm for the second path and having a third channel width that supports a single transverse optical mode, a second splitter portion for combining optical signals of the at least first and second paths, an output portion for transmitting a resultant combination of optical signals from the second splitter and having a fourth channel width, and wherein the second channel width is larger than the fourth channel width.