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58 EE|Times EUROPE

Semiconductor Lasers: Innovations, Applications, and Directions

particularly for datacom interconnects and
computing applications, as well as for LiDAR
used in future autonomous electric vehicles.
Therefore, we see a high demand for dense
integration of photonics with electron-
ics. Integrated optoelectronics using III-V
compound semiconductor technology on
low-cost silicon substrates has shown exciting
possibilities. One key driver for using silicon
for photonics is the advantages of scaling up
to 300-mm wafer CMOS processes; this drives
the cost down significantly — up to 60%. A
further advantage is in the low-loss silicon
waveguides that connect various photonic
elements, including lasers, modulators, pho-
todetectors, and other passive devices.
Improvements in the yield of silicon
photonics-based devices coupled with the
application-driven requirements enable the
integration of a larger number of devices on
a single silicon photonic integrated circuit
[PIC]. We expect that heterogeneous integra- are increasingly gaining share within the EETE: What are the trends in high-power
tion [direct wafer bonding] will be preferred in materials-processing market because of the laser applications?
the coming years. greater precision, processing speeds, and Yole: Currently, we observe more dynamics
flexibility this technology enables. EELs for in additive manufacturing, semiconductor
EETE: How will lasers contribute to the kilowatt material processing are projected to manufacturing, and medical applications,
enhancement of AI and ML applications? grow from US$409 million in 2020 to especially in dermatology and surgery.
Yole: Artificial-intelligence and US$468 million in 2026 at a compound annual The additive manufacturing industry
machine-learning applications primarily growth rate for the period of 2%. This moder- is going through extraordinary times. 3D
use silicon chips in deep neural networks. AI ate growth will continue to be driven by new printing is enabling digital supply chains
chips [also called AI accelerators] are specially applications as well as the automated- and establishing itself as a viable technology
designed accelerators for applications based manufacturing trend. for on-demand manufacturing. In consumer
on artificial neural networks [ANNs]. Most electronics, laser micromachining is widely
commercial ANN applications are deep- EETE: What future innovations do you used for high-volume semiconductor man-
learning applications. The main system trends see for edge-emitting lasers? ufacturing to achieve the desired precision,
in data centers are disaggregation, scale-up, Yole: It is important to emphasize that quality, throughput, and cost per machined
heterogeneous acceleration, and the conver- edge emitters make up a core technology of part. For devices such as smartphones, tablets,
gence of high-performance computing [HPC] multiple laser systems targeting many end and wearables, laser micromachining is used
and the cloud. The goal is to bring technol- markets. Generally, edge-emitter technology in the fabrication of semiconductor chips and
ogies to the market that can contribute to has been driven by multiple laser applications’ their packaging, electronic components, and
building more efficient systems for workloads demands on intrinsic laser diode parameters the circuitry connecting these components in
in HPC and AI training/inference. As HPC for different end markets. the form of PCBs.
moves into the cloud, the systems will require For example, the traffic in data centers is The manufacture of high-resolution
a low-latency and high-bandwidth commu- growing exponentially. Therefore, for optical touchscreen displays also relies on many
nication fabric for AI accelerators. Integrated communication, it is essential to increase the laser-micromachining processes. The camera
lasers will serve for optical interconnection bandwidth and speed of the optical mod- windows, the sensors, and even the external
of HPC and AI/ML workloads. This solution is ules at all levels of DC infrastructure while enclosure utilize laser micromachining to
very new and is still in R&D. simultaneously decreasing the footprint and achieve the required machined results.
power consumption. In terms of discrete Lasers for medical applications reflect
EETE: Do you think the laser materials- laser diodes, innovations stem from the recent research on the laser’s principles,
processing market is a potential area DFB [distributed-feedback] laser design by technologies, and applications in diagnos-
of growth? enhancing the multi-quantum well of EA tics, therapy, and surgery. A wide variety of
Yole: The laser-based materials-processing [electro-absorption] modulators for high- lasers serve medical applications, depending
market is a traditional laser market. Laser speed operations and reducing the inductance on such factors as the optical wavelength,
materials processing has been used for over of the wires by bonding short wires for high output power, and pulse format required. In
four decades and plays a vital role in modern bandwidth. Future innovations will likely many cases, the laser wavelength is chosen
manufacturing and the economy. While result in the integration of PICs, also known such that certain specific substances, such
laser cutting, welding, marking, and drilling as silicon photonics. Integrating complex as pigments in tattoos or caries in teeth,
processes have reached maturity and wide electro-optical circuits onto a single silicon will absorb light more strongly than the
industrial acceptance, new developments chip enables the creation of new form factors surrounding tissue so that they can be more
in recent years in additive manufacturing while increasing the bandwidth and distance, precisely targeted. ■
and micro/nanofabrication have enabled significantly improving power efficiency and
new capabilities that lasers can bring to the density in ways that simply could never be Maurizio Di Paolo Emilio is editor-in-chief of
manufacturing industry. Laser-based systems addressed with discrete devices. Power Electronics News and EEWeb.

NOVEMBER 2021 | www.eetimes.eu