August 2022 Vol. 20 No. 882022

https://www.ntt-review.jp/archive/2022/202208.html

View from the Top
Akira Shimada, President and Chief Executive Officer, NTT

Front-line Researchers
Mitsuaki Akiyama, Senior Distinguished Researcher, NTT Social Informatics Laboratories

Rising Researchers
Hiroshi Yamazaki, Distinguished Researcher, NTT Device Technology Laboratories

Feature Articles
Device Technologies for Enabling the All-Photonics Network
High-output Optical Transmitter and High-sensitivity Optical Receiver for 400-Gbit/s 40-km
Fiber-amplifier-less Transmission
C+L-band Colorless, Directionless, Contentionless Reconfigurable Optical Add/Drop Multiplexingfor High-capacity Network Flexibility
Development of Membrane Optical Modulators for IOWN
Observation of Exceptional Point Degeneracy with Current-injected Photonic Crystal Lasers

Feature Articles
Optical Device Technologies for Next-generation Computing
Using Light
Optical Device Technology for Next-generation Computing Using Light
Broadband Continuous-wave Optical Quadrature Squeezer for Ultra-fast Optical Quantum
Computers
Optical Circuit Technologies for Next-generation Computing Using Light
Photonic Implementation of Reservoir Computing

Regular Articles
Business Design Support Technology to Promote Digital Transformation

Global Standardization Activities
Report on WTSA-20 (World Telecommunication Standardization Assembly)

Practical Field Information about Telecommunication Technologies
Development of the Hikari Denwa Fault-isolation Tool for Voice Over IP Services

View from the Top

Akira Shimada, President and Chief Executive Officer, NTT▼Abstract
With people at its core, the NTT Group defines the capabilities it aims to achieve asservice expertise, technical expertise, and intelligence. All 330,000 NTT Group
employees―working in approximately 90 countries and regions―are accelerating
the group’s self-transformation into a new NTT that is open, global, and innovative
to be valuable to all stakeholders, including customers, shareholders, local
communities, and employees. We asked Akira Shimada, president and chief
executive officer of NTT, who took up the post in June 2022, about the details of theguidelines that he announced at his inaugural press conference and his thoughts
on what it means to be a top executive.

Feature Articles
Device Technologies for Enabling the All-Photonics Network

High-output Optical Transmitter and High-sensitivity Optical
Receiver for 400-Gbit/s 40-km Fiber-amplifier-less Transmission▼Abstract
We developed a high-output optical transmitter anda high-sensitivity optical receiver for long-distancetransmission in the All-Photonics Network that isbeing promoted under IOWN (the Innovative Opticaland Wireless Network). This article introduces the400-Gbit/s optical transmitter with a semiconductor
optical amplifier-assisted extended-reachelectro-absorption modulator integrated distributed
feedback laser called AXEL, a key device for higher
optical output, and the 400-Gbit/s optical receiverwith an avalanche photodiode, a key device forhigher sensitivity.

100-Gbit/s
electrical signal
input

Currentinjection

Current
injection

100-Gbit/s
optical signal

Amplification

Conversion tooptical signal

SOA

EA modulator

Single-wavelength
light generation

DFB laser

Feature Articles
Optical Device Technologies for Next-generation Computing Using Light

Optical Device Technology for Next-generation Computing
Using Light▼Abstract
The performance of conventional computers,
which have supported the infrastructure of ourdigital society and developed in accordance with
Moore’s law, seems to be approaching its limits.
To solve many social issues and achieve a safe,
secure, and prosperous society, next-generation
computers with performance far beyond that ofconventional computers, such as quantumcomputers, are expected. This article outlines
the possibilities of next-generation computersthat compute using light and optical device
technologies introduced in the Feature Articlesof this issue.

Signal processing using light

Information processing using light

Digital filter
Intradyne detection~ operation for signal frequency
Splitter, wavelength filter

Optical analog circuit
Homodyne detection, autocorrelation~ operation for optical wave frequency

Optical digital filter

Optical neuralnetwork
Optical communications
Continuous signals(superimposed on light)

Symbols indigital signal

Optical circuit forneural network

Optical circuit for quantum
information processing

Optical reservoircomputing
Optical quantum computing
Analogue wave(lightwave)

Granularity of information processed using light

Photons