Robert J. Mears

Last updated
Robert J. Mears
Born
England
Occupation(s)Physicist and engineer
Known forInvented EDFA, founded Atomera.
Notable work EDFA, Mears Silicon Technology

Robert J. Mears is an English physicist and engineer. In the 1980s, Dr. Mears invented and demonstrated the Erbium Doped Fiber Amplifier (EDFA) with the help of members of the Optoelectronics Research Group led by Alec Gambling and David Payne. [1] In 2001 he founded Atomera, and as CTO led the invention and development of Mears Silicon Technology (MST), a method for improving the mobility and other characteristics of semiconductor devices. Mears has authored and co-authored more than 250 publications and patents, and is co-inventor of 46 granted US patents. [2] He is an Emeritus Fellow of Pembroke College, Cambridge.

Contents

Education

Mears graduated with a BA(1982), MA(1986) in physics from Oxford University. In 1982, he moved to Southampton University to study for the PhD degree. There he conceived and demonstrated the first EDFA and various fibre lasers. [3] Mears was awarded the PhD degree in 1987 for his thesis entitled “Development of rare-earth doped fibre lasers and amplifiers”. He was elected to the Maudslay Research Fellowship at Pembroke College, Cambridge in May 1987 and the following year was elected to the faculty of Cambridge University Engineering Department, later being appointed Reader in Photonics. [4] He founded Atomera (formerly known as Mears Technologies) in 2001. He remains an Emeritus Fellow of Pembroke College, Cambridge. [5]

EDFA

In 1986 and 1987, Mears co-authored two papers published in the Institute of Electrical Engineers (IEE) Journal “Electronics Letters” [6] [7] entitled "Low-threshold tunable CW and Q-switched fiber laser operating at 1.55μm" and “Low-noise Erbium-doped fibre amplifier at 1.54μm”. These two papers are the first on gain in erbium-doped single mode fibers and the EDFA (Erbium-Doped Fibre Amplifier). Dr. Mears was a co-recipient of the 1986 IEE Electronics Letters Premium. Before these works were published, patents covering the fabrication of the fiber and the laser and amplifier were filed on the UK and US. [8] The Book Patents, Inventions and the Dynamics of Innovation: A Multidisciplinary Study describes Dr. Mears invention as a “seminal invention”.[ citation needed ]

Atomera

In 2001, Mears founded the semiconductor company, Mears Technologies, which was later renamed Atomera. The firm developed the MST platform, a way to make silicon transistors to be more efficient without shrinking the manufacturing process. [9] This is achieved by inserting oxygen layers during silicon epitaxy of the channel layer.

Further reading

Related Research Articles

<span class="mw-page-title-main">Erbium</span> Chemical element, symbol Er and atomic number 68

Erbium is a chemical element; it has symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare-earth element, originally found in the gadolinite mine in Ytterby, Sweden, which is the source of the element's name.

<span class="mw-page-title-main">Transistor</span> Solid-state electrically operated switch also used as an amplifier

A transistor is a semiconductor device used to amplify or switch electrical signals and power. It is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more in miniature form are found embedded in integrated circuits. Because transistors are the key active components in practically all modern electronics, many people consider them one of the 20th century's greatest inventions.

<span class="mw-page-title-main">Semiconductor device</span> Electronic component that exploits the electronic properties of semiconductor materials

A semiconductor device is an electronic component that relies on the electronic properties of a semiconductor material for its function. Its conductivity lies between conductors and insulators. Semiconductor devices have replaced vacuum tubes in most applications. They conduct electric current in the solid state, rather than as free electrons across a vacuum or as free electrons and ions through an ionized gas.

<span class="mw-page-title-main">MOSFET</span> Type of field-effect transistor

The metal–oxide–semiconductor field-effect transistor is a type of field-effect transistor (FET), most commonly fabricated by the controlled oxidation of silicon. It has an insulated gate, the voltage of which determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. The term metal–insulator–semiconductor field-effect transistor (MISFET) is almost synonymous with MOSFET. Another near-synonym is insulated-gate field-effect transistor (IGFET).

<span class="mw-page-title-main">Optical amplifier</span> Device that amplifies an optical signal

An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from the cavity is suppressed. Optical amplifiers are important in optical communication and laser physics. They are used as optical repeaters in the long distance fiber-optic cables which carry much of the world's telecommunication links.

<span class="mw-page-title-main">Wavelength-division multiplexing</span> Fiber-optic communications technology

In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths of laser light. This technique enables bidirectional communications over a single strand of fiber as well as multiplication of capacity.

<span class="mw-page-title-main">Photonics</span> Technical applications of optics

Photonics is a branch of optics that involves the application of generation, detection, and manipulation of light in form of photons through emission, transmission, modulation, signal processing, switching, amplification, and sensing. Photonics is closely related to quantum electronics, where quantum electronics deals with the theoretical part of it while photonics deal with its engineering applications. Though covering all light's technical applications over the whole spectrum, most photonic applications are in the range of visible and near-infrared light. The term photonics developed as an outgrowth of the first practical semiconductor light emitters invented in the early 1960s and optical fibers developed in the 1970s.

All-silica fiber, or silica-silica fiber, is an optical fiber whose core and cladding are made of silica glass. The refractive index of the core glass is higher than that of the cladding. These fibers are typically step-index fibers. The cladding of an all-silica fiber should not be confused with the polymer overcoat of the fiber.

Sir David Neil Payne CBE FRS FREng is a British professor of photonics who is director of the Optoelectronics Research Centre at the University of Southampton. He has made several contributions in areas of optical fibre communications over the last fifty years and his work has affected telecommunications and laser technology. Payne’s work spans diverse areas of photonics, from telecommunications and optical sensors to nanophotonics and optical materials, including the introduction of the first optical fibre drawing tower in a university.

<span class="mw-page-title-main">Solid-state laser</span> Laser which uses a solid gain medium

A solid-state laser is a laser that uses a gain medium that is a solid, rather than a liquid as in dye lasers or a gas as in gas lasers. Semiconductor-based lasers are also in the solid state, but are generally considered as a separate class from solid-state lasers, called laser diodes.

This is a list of acronyms and other initialisms used in laser physics and laser applications.

Optical networking is a means of communication that uses signals encoded in light to transmit information in various types of telecommunications networks. These include limited range local-area networks (LAN) or wide area networks (WANs), which cross metropolitan and regional areas as well as long-distance national, international and transoceanic networks. It is a form of optical communication that relies on optical amplifiers, lasers or LEDs and wavelength-division multiplexing (WDM) to transmit large quantities of data, generally across fiber-optic cables. Because it is capable of achieving extremely high bandwidth, it is an enabling technology for the Internet and telecommunication networks that transmit the vast majority of all human and machine-to-machine information.

A fiber laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium and holmium. They are related to doped fiber amplifiers, which provide light amplification without lasing.

<span class="mw-page-title-main">Fiber-optic communication</span> Transmitting information over optical fiber

Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. The light is a form of carrier wave that is modulated to carry information. Fiber is preferred over electrical cabling when high bandwidth, long distance, or immunity to electromagnetic interference is required. This type of communication can transmit voice, video, and telemetry through local area networks or across long distances.

A distributed-feedback laser (DFB) is a type of laser diode, quantum-cascade laser or optical-fiber laser where the active region of the device contains a periodically structured element or diffraction grating. The structure builds a one-dimensional interference grating, and the grating provides optical feedback for the laser. This longitudinal diffraction grating has periodic changes in refractive index that cause reflection back into the cavity. The periodic change can be either in the real part of the refractive index or in the imaginary part. The strongest grating operates in the first order, where the periodicity is one-half wave, and the light is reflected backwards. DFB lasers tend to be much more stable than Fabry–Perot or DBR lasers and are used frequently when clean single-mode operation is needed, especially in high-speed fiber-optic telecommunications. Semiconductor DFB lasers in the lowest loss window of optical fibers at about 1.55 μm wavelength, amplified by erbium-doped fiber amplifiers (EDFAs), dominate the long-distance communication market, while DFB lasers in the lowest dispersion window at 1.3 μm are used at shorter distances.

Filling factor, is a quantity measuring the efficiency of absorption of pump in the core of a double-clad fiber.

<span class="mw-page-title-main">IPG Photonics</span> U.S. fiber laser company

IPG Photonics is an American manufacturer of fiber lasers. IPG Photonics developed and commercialized optical fiber lasers, which are used in a variety of applications including materials processing, medical applications and telecommunications. IPG has manufacturing facilities in the United States, Germany, Russia and Italy.

A dopant is a small amount of a substance added to a material to alter its physical properties, such as electrical or optical properties. The amount of dopant is typically very low compared to the material being doped.

An erbium-doped waveguide amplifier is a type of an optical amplifier enhanced with erbium. It is a close relative of an EDFA, erbium-doped fiber amplifier, and in fact EDWA's basic operating principles are identical to those of the EDFA. Both of them can be used to amplify infrared light at wavelengths in optical communication bands between 1500 and 1600 nm. However, whereas an EDFA is made using a free-standing fiber, an EDWA is typically produced on a planar substrate, sometimes in ways that are very similar to the methods used in electronic integrated circuit manufacturing. Therefore, the main advantage of EDWAs over EDFAs lies in their potential to be intimately integrated with other optical components on the same planar substrate and thus making EDFAs unnecessary.

Masataka Nakazawa is a Japanese researcher in optical communication engineering. He is a distinguished professor at Tohoku University in Japan. His pioneering work on erbium-doped fiber amplifier (EDFA) has made a significant contribution to the development of global long-distance, high-capacity optical fiber network.

References

  1. ↑ "People at the ORC". ORC. Retrieved 30 November 2016.
  2. ↑ "Inventor Robert J. Mears". Google. Retrieved 30 November 2016.
  3. ↑ "Profile". Bloomberg.com. Retrieved 30 November 2016.
  4. ↑ "Scientific Imaging Group". Cambridge University.
  5. ↑ "Emeritus Fellows". Pembroke College. Retrieved 30 November 2016.
  6. ↑ Xu, N.; Damrongplasit, N.; Takeuchi, H.; Stephenson, R. J.; Cody, N. W.; Yiptong, A.; Huang, X.; Hytha, M.; Mears, R. J.; Liu, T. J. K. (1 December 2012). "MOSFET performance and scalability enhancement by insertion of oxygen layers". 2012 International Electron Devices Meeting. pp. 6.4.1–6.4.4. doi:10.1109/IEDM.2012.6478990. ISBN   978-1-4673-4871-3.{{cite book}}: |website= ignored (help)
  7. ↑ Mears, R. J.; Xu, N.; Damrongplasit, N.; Takeuchi, H.; Stephenson, R. J.; Cody, N. W.; Yiptong, A.; Huang, X.; Hytha, M.; King-Liu, T. J. (1 June 2012). "Simultaneous carrier transport enhancement and variability reduction in Si MOSFETs by insertion of partial monolayers of oxygen". 2012 IEEE Silicon Nanoelectronics Workshop (SNW). pp. 1–2. doi:10.1109/SNW.2012.6243326. ISBN   978-1-4673-0997-4.
  8. ↑ Mears, Robert J.; Reekie, Laurence; Poole, Simon B.; Payne, David N. (1990). "Fibre-optic lasers and amplifiers". Google. Retrieved 30 November 2016.
  9. ↑ "Atomera Incorporated Announces Closing of $6 Million Convertible Note Offering". Liquid Venture. 11 April 2016. Retrieved 30 November 2016.
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