Gallium arsenide supports efficient 1300-nm electro-absorption waveguide modulator

A grou¥at the University of California at San Diego (La Jolla, CA) has demonstrated what they believe is the first high-speed multiple-quantum-well (MQW) electro-absorption

Oct 1st, 1997

Gallium arsenide supports efficient 1300-nm electro-absorption waveguide modulator

A grou¥at the University of California at San Diego (La Jolla, CA) has demonstrated what they believe is the first high-speed multiple-quantum-well (MQW) electro-absorption

waveguide modulator using a relatively thin step-graded relaxed buffer on a gallium arsenide (GaAs) substrate. The modulator was designed and characterized at 1300 nm for microwave-

signal transmission on an analog fiberoptic link and offers the potential for monolithic

integration with other optoelectronic devices on GaAs substrates.

The waveguide modulator exhibited an electro-optic slope efficiency as high as 0.56 V?1 at an optimum bias of -1.79 V with an average intensity transmission of 46%, which is as high as that obtained in other 1300-nm MQW structures on indium phosphide (InP) substrates. Its RC-limited 3-dB bandwidth was 20 GHz, with an optical saturation intensity in excess of

17 mW. The modulator structure had a lattice constant 2.5% larger than that of GaAs and was grown on a 0.7-?m-thick three-stage compositionally step-graded InzAl1?zAs relaxed buffer.

More in Fiber Optics
FIGURE 1. The tip of a 30,000-core optical fiber bundle is shown next to an Australian 5 cent coin for scale (left) and a zoomed-in image (right) reveals a small region of the fiber bundle facet (dashed red box in left). Each core is roughly 2 µm in diameter and separated from its neighbors by an average of 3.3 µm.
Fiber Optics
Fiber-optic Components: Fiber-optic bundles provide 3D stereo imaging

With each fiber acting as an independent pixel, coherent fiber bundles transmit more information than just a 2D representation of an image; specifically, the spatial light field faithfully encodes 3D stereo data.

Aug 13th, 2019
FIGURE 1. The mode of operation of a DCFC for extraction of fluorescence emission is shown.
Detectors & Imaging
Optical Coherence Tomography/Fluorescence Imaging: Fiber assembly enables efficient multimodal endoscopy

Double-clad fiber couplers (DCFCs) enable seamless and efficient combinations of modalities for robust fiber-based imaging and other biomedical applications.

Aug 13th, 2019
In the first 5 years of system rollouts, 5G subscribers will significantly outpace 4G subscribers.
Fiber Optics
5G subscribers in Asia, North America to surpass 1.1 billion by 2023--triple the 4G pace

In contrast, 4G's subscriber base in the two regions amounted to just 417 million units in 2014 five years after that technology’s initial deployment.

Gail Overton
Jul 25th, 2019
FIGURE 1. A schematic representation details the spectral components of scattered light within an optical fiber.
Fiber Optics
Fiber-optic Sensing: Smart fiber-optic sensing systems enhance physical border walls and fences

Distributed fiber-optic sensing architectures complement physical borders by providing accurate, cost-effective, real-time monitoring of perimeter intrusions.

Jul 1st, 2019
Test & Measurement
On-chip laser-based quantum device generates true random numbers

A photonic integrated circuit containing two laser diodes whose outputs are interfered and measured produces truly random numbers at gigahertz rates.

John Wallace
Jul 1st, 2019
John Lewis 720
Commentary
Fiber sensing

John Lewis
Jul 1st, 2019
Cisco plans to acquire Acacia Communications to expand its optical networking portfolio.
Fiber Optics
Cisco to acquire Acacia for $2.6B, boosting coherent optical and interconnect solutions

Cisco says that innovation across software, silicon, and optics is fueling its initiative to make networks smarter, simpler, and more secure.

Gail Overton
Jul 10th, 2019
SPIE, the international society for optics and photonics, has agreed to purchase Xmark Media, including Photonex Europe, Photonex Scotland, Photonex London, and Vacuum Expo.
Optics
SPIE to acquire UK’s Xmark Media and its Photonex events

SPIE, the international society for optics and photonics, has agreed to purchase Xmark Media, including Photonex Europe, Photonex Scotland, Photonex London, and Vacuum Expo

Gail Overton
Jun 21st, 2019
A tiny fiber-optic probe and methods from the University of California, Riverside are improving the ability to understand molecular bonds for a host of important applications.
Fiber Optics
Fiber-optic probe maps molecular bonds with 1 nm resolution

UC Riverside engineers have developed a new technology to tunnel light into the quantum realm with unprecedented efficiency.

Gail Overton
Jun 12th, 2019
1906 Lfw Jl 1a
Lasers & Sources
LASER World of PHOTONICS 2019: Inspiring

The depth and diversity of photonics technologies and products on display is an exciting reminder of the pivotal role of the world’s leading photonics tradeshow.

John Lewis
Jun 7th, 2019