Nippon Telegraph and Telephone Corporation

Josuke Ozaki

Yoshihiro Ogiso

Hiromasa Tanobe

Shigeru Kanazawa

Yuta Ueda

Nobuhiro Kikuchi

Yasuaki Hashizume

Shinsuke Nakano

Eiichi Yamada

Mitsuteru Ishikawa

Norihide Kashio

Shogo Yamanaka

Nobuhiro Nunoya

Akinori Fujino

Masaki Kohtoku

Naonori Ueda

A high-frequency line structure includes: a high-frequency line substrate; ground lead pins fixed to ground ends provided in a bottom surface of the high-frequency line substrate; and signal lead pins fixed to signal line ends provided in the bottom surface of the high-frequency line substrate, wherein the signal lead pins are arranged between the ground lead pins, the signal lead pins have a structure in which each of the signal lead pins springs up in a direction toward a side on which the high-frequency line substrate is arranged, from a horizontal plane to which bottom surfaces of the ground lead pins pertains, and spring-up heights in the structure in which the respective signal lead pins spring up are substantially the same.

High-frequency line structure, subassembly, line card, and method for manufacturing line structure

A semiconductor optical modulator in which a radio frequency (RF) line which is disposed parallel to an optical waveguide and is a differential configuration for transmitting an RF modulation signal, a connecting pad which is formed in the same direction continuously with the RF line, and a termination resistor which has two rectangular resistors for differentially terminating the RF modulation signal from the connecting pad are linearly disposed, and terminated on-chip, and the RF line which forms a differential pair immediately after passing through the termination resistor is short-circuited.

Semiconductor optical modulator

A high-frequency line substrate is mounted on a printed circuit board. The printed circuit board includes a first high-frequency line. The high-frequency line substrate includes a second high-frequency line and lead pins that connect the first high-frequency line and the second high-frequency line. At the contact portions between the signal lead pins and the second high-frequency line of the high-frequency line substrate, and at the contact portions between the ground lead pins and the second high-frequency line of the high-frequency line substrate, the height of the ground lead pins from an upper surface of the printed circuit board is greater than the height of the signal lead pins.

High-frequency line structure with lead pin-connected substrates

Provided is a high-speed optical transmission-reception apparatus including a digital-signal processing circuit and optical modulation and optical reception modules, in which a flexible printed circuit is used as a high-frequency interface for the optical modulation and optical reception modules, a mechanism for connecting the high-frequency line pattern to the flexible printed circuit is provided on a package substrate of the digital-signal processing circuit, and the package substrate and the optical modulation and optical reception modules are connected by the flexible printed circuit.

High-speed optical transceiver

A semiconductor Mach-Zehnder optical modulator includes input-side lead-out lines, phase modulation electrode lines, and electrodes that apply modulation signals propagating through the phase modulation electrode lines to waveguides, respectively. The semiconductor Mach-Zehnder optical modulator further includes a conductive layer between a substrate and the waveguides, a plurality of first wiring layers connected to the conductive layer, and a second wiring layer that connects an electrode pad and the plurality of first wiring layers.

Semiconductor Mach-Zehnder optical modulator and IQ modulator

Phase modulation electrode lines of a semiconductor Mach-Zehnder optical modulator are formed along waveguides. Output-side lead lines are bent in a direction crossing the extending direction of the waveguides in the plane of a dielectric layer and are connected to terminal resistors. The output-side lead lines are formed in a predetermined width corresponding to a desired impedance and make the width narrower than the predetermined width only in the bent portions and portions where the output-side lead lines crosses the waveguides.

In a terminator, a midpoint electrode is provided between a first signal electrode and a second signal electrode, a first resistor is connected between the first signal electrode and the midpoint electrode, a second resistor is connected between the second signal electrode and the midpoint electrode, a first GND electrode is provided on a side opposite to the side where the first resistor is provided with the first signal electrode interposed therebetween, a second GND electrode is provided on the side opposite to the side where the second resistor is provided with the second signal electrode interposed therebetween, and capacitances in the terminator are formed between the first signal electrode and the midpoint electrode, between the second signal electrode and the midpoint electrode, between the first signal electrode and the first GND electrode, and between the second signal electrode and the second GND electrode.

Optical modulator module

An optical module includes: a Peltier module; an optical semiconductor element mounted on the Peltier module; and a driver that drives high-frequency lines of the optical semiconductor element. The optical semiconductor element includes: optical circuits providing a function of an optical interferometer and the high-frequency lines. Cooling performance of the Peltier module in a region in vicinity of the driver is higher than the cooling performance in other regions.

Optical module

Provided is an optical modulator manufacturing method capable of determining the quality of an optical modulator having MMI waveguides and realizing improvement in yield during manufacturing. Here, in waveguide fabrication processes, hard mask material deposition, soft mask material application, exposure, and hard mask fabrication are executed, and then in hard mask width length measurement, the hard mask width for fabricating the MMI waveguide is measured at one or more locations. In hard mask width quality determination based on machine learning results, the quality of optical characteristics of the chip is predicted and determined in advance, based on sample data created in advance by analyzing a relationship between the hard mask width and optical characteristics of the optical modulator, depending on whether the hard mask width is present in a permissible range of the sample data. Depending on the result of the above-mentioned determination.

Manufacturing method of optical modulator

Provided is an IQ optical modulator including a nest-type MZ optical waveguide having optical modulation regions of I channel and Q channel End portions of an input optical waveguide and an output optical waveguide of the IQ optical modulator are located on a same edge face of a chip of the IQ optical modulator, an optical cross waveguide is included in which an optical waveguide between a first optical combiner and a second optical combiner of the nest-type MZ optical waveguide and the input optical waveguide cross each other, a first optical divider is provided between the I-channel optical modulation region and the Q-channel optical modulation region, and a light propagation direction in the first optical divider and a light propagation direction in the optical modulation regions are opposite to each other.

IQ optical modulator

In the adjustment method of optical coupling for an optical integrated circuit according to the present disclosure, the optimal adjustment position of optical coupling is determined on the basis of, for example, a sum of a plurality of photocurrents at electrodes on arm waveguides respectively formed on the plurality of MZIs in the polarization-multiplexing IQ modulator. According to the maximum value of the sum of the plurality of photocurrents, the light condensing spot position is adjusted to the center position of the end face core of the optical waveguide of the integrated chip. Typically, the light condensing spot position is adjusted to the center of the end face core by displacing the two input lenses.

Optical coupling method

A semiconductor Mach-Zehnder optical modulator includes input side lead-out lines, phase modulation electrode lines, output side lead-out lines, electrodes that apply modulation signals propagating through the phase modulation electrode lines to respective waveguides, and ground lines. Furthermore, at least one n-type semiconductor layer or p-type semiconductor layer is formed between a substrate and a dielectric layer in a lower layer under the output side lead-out lines intermittently along the output side lead-out lines.

Semiconductor Mach Zehnder optical modulator

Reflection between a Mach-Zehnder modulator and a termination resistor is suppressed. An optical modulator includes a differential drive open collector driver IC, a differential drive semiconductor Mach-Zehnder modulator, and a differential terminator. The Mach-Zehnder modulator includes waveguides and a differential high-frequency line. The differential terminator includes a differential high-frequency line and termination resistors. The differential high-frequency line includes a capacity provided at least one of between signal lines and between a signal line and a ground line.

Optical modulator

Provided is an optical modulator having an optical modulation high frequency line through which a high frequency electrical signal can be efficiently input to an optical modulation region and which is in a broadband. High frequency lines of an optical modulator, that is, an input high frequency line, an optical modulation high frequency line, and an output high frequency line have a line configuration in which each of the input high frequency line and the output high frequency line is divided into a plurality of segments, and adjacent segments of the plurality of the segments have different characteristic impedances and propagation constants. The input high frequency line and the output high frequency line may be implemented by changing a width or a thickness of a signal electrode formed on a dielectric forming a micro-strip line between adjacent segments. The characteristic impedances and the propagation constants may be changed by changing a dielectric constant of the dielectric instead of changing the width or the thickness of the signal electrode.

A second substrate is formed on a first substrate. The second substrate includes a Mach-Zehnder modulation unit and a coplanar line. Further, the second substrate is formed on and bonded to the first substrate via an adhesive layer made of a non-conductive adhesive. The Mach-Zehnder modulation unit has an optical modulation region by an electro-optic effect. The coplanar line transmits a modulated signal to the optical modulation region.

Growing community of inventors

Atsugi, Japan

Josuke Ozaki