An electro-optic modulator/mode-converter with slow wave electrode is formed on a semiconductor substrate incorporating a waveguide interposed between a pair of spaced parallel conductor strips each provided with fins projected toward the other electrode and in position relative to the waveguide to electro-optically affect the waveguide when voltage is applied to the conductor strips. The modulator requires significantly less power and operates at higher frequency than Mach-Zehnder type slow wave modulators.

Electro-optic modulator

In various embodiments, a monolithic integrated transmitter, comprising an on-chip laser source and a modulator structure capable of generating advanced modulation format signals based on amplitude and phase modulation are described.

Chip-based advanced modulation format transmitter

High speed electro-optic modulator designs (600, 2700, 2800) are presented. One design (600) includes first (612) and second (614) electrodes offset from each other and further includes a substrate supporting a laterally confined ferroelectric material (606), for example, LiNbO3. The confined ferroelectric material, in turn, supports first (608) and second (610) optical waveguides. In a second design (2700), a thin ferroelectric film (2702) is fabricated on a substrate that supports the first (2708) and second (2710) electrodes. The thin ferroelectric film has a first thickness in which the first (2704) and second (2706) optical waveguides are supported, and a second thickness under a portion of the electrodes. The second thickness, for example, may be zero. A third design (2800) includes a thin ferroelectric film (2802) fabricated on a substrate and supporting first (2808) and second (2810) electrodes. The thin ferroelectric film has a reduced thickness in at least one electrode gap region.

High speed electro-optic modulator

An optical device assures high speed drive, excellent temperature stability, low drive voltage and small crosstalk and insertion loss. The optical device includes a single crystal substrate which is used as a conductive or semiconductive lower electrode, an epitaxial buffer layer consisting of an oxide provided on the single crystal substrate, an epitaxial optical waveguide layer with an oxide ferroelectric material having an electro-optic effect which is provided on the buffer layer and which has a channel optical waveguide of which an optical path is switched when a voltage is applied to the branching portion between an optical path for incident light and an optical path for outgoing light, and a couple of upper electrodes for applying a voltage to the branching portion of the channel optical waveguide.

Optical device, driving method of optical device and manufacture of optical device

The Mach-Zehnder type all-optical device for controlling a signal light with a control light, includes two arms for constituting a Mach-Zehnder configuration, each of the arms being constituted at least partially of material having third order optical nonlinearity, and an introducer of a control light to a portion of each of the arms revealing the optical nonlinearity.

Symmetric Mach-Zehnder all-optical device

Optical device including an optical waveguide composed of a LiTaO3 monocrystalline substrate and a LiNbO3 monocrystalline thin film waveguide formed on the surface of the substrate, with the lattice length of the LiNbO3 monocrystalline thin film waveguide and the LiTaO3 monocrystalline substrate being matched with each other, and an electrode provided on at least one of the branched sections of the waveguide extending along the optical axis thereof for changing a refractive index of the waveguide. The optical device having the optical waveguide has excellent electro-optic effects and a resistance to optical damage as well as an advanced modulation efficiency and a stable amplitude modulation.

Masanori Nakamura

Papers

Optical waveguide and optical waveguide device