Emrah Acar photo Solomon Assefa photo TYMON BARWICZ photo
William M. J. Green photo Jens Hofrichter photo Jonathan E. (Jon) Proesel photo
 Jessie C. Rosenberg photo Alexander V. Rylyakov photoYurii A. Vlasov photo
Chi Xiong photo

Research Areas

Additional information

2012 IEDM postdeadline paper


2012 CLEO Plenary talk


2012 IEEE Comm. Mag., Silicon Nanophotonics Beyond 100G


2011 IBM R&D Journal: Technologies for Exascale systems


2010 SEMICON Talk: CMOS Nanophotonics for Exascale


2008 ECOC Tutorial: On-Chip Si Nanophotonics

Project Name

Silicon Integrated Nanophotonics


On July 30, 2010 IBM Research scientists and colleagues at Columbia University announced the demonstration of a mid-infrared (mid-IR) optical parametric amplifier, which has been designed and built using ultra-compact silicon nanophotonic waveguides. The resutls of this work are published in the journal Nature Photonics.

An amplifier of this type can be applied to boost the intensity of very weak information-carrying optical signals. However, unlike the glass-fiber-based optical amplifiers which are commonly used in today’s near-IR fiber optic telecommunication systems, IBM’s new amplifier is constructed using chip-scale ultra-compact silicon nanophotonic waveguides. The silicon amplifier is specifically designed to operate at longer wavelengths in the mid-IR spectrum, and can boost signals over a broad wavelength range from 2050-2250 nm, to as much as 400-times their original strength.

The capabilities of this device can potentially be applied to improve the integrity of optical signals relevant to a wide range of mid-IR applications, including sensors for monitoring of pollutant concentrations within the environment, instruments for high-sensitivity medical diagnostics and imaging, and point-to-point free-space optical communication.

Our work illustrates that the silicon nanophotonic tool set, developed at IBM for on-chip optical interconnects, can be leveraged to enable an entirely new class of technologies tailored to the mid-IR spectrum. By utilizing IBM’s established wafer-scale fabrication processes for silicon nanophotonics, it is possible to envision the development of chip-scale, low-cost, multi-function photonic integrated circuits targeting these mid-IR applications.



Image Gallery. Click to enlarge

Optical Parametric Amplifier on a Chip

Optical Parametric Amplifier vision

Figures captions



Image 1
Mid-Infrared Horizons for Silicon Nanophotonics: An artist’s rendering of an array of silicon nanophotonic waveguides, carrying mid-infrared signals.

Optical Parametric amplifier cross-section

Optical Parametric amplifier cross-section

Figures captions



Image 2
Scanning electron microscope cross-sectional image of the 700 nm x 425 nm silicon waveguide. The color-map illustrates the Ey electric field component of the fundamental transverse-magnetic mode at a wavelength of 2200 nm. The silicon (Si) waveguide core is labeled in the image, as well as the silicon dioxide (SiO2) and silicon oxynitride (SiOxNy) cladding layers.

Frequently Asked Questions

1. What has IBM announced today?
2. How is this advancement related to IBM’s Silicon On-Chip Optical Interconnects Project?
3. How does it work?
4. Why is this a significant advancement?
5. When will this technology be available to the general public?
6. What are the next steps?



1. What has IBM announced today?

As described in a paper published recently in the journal Nature Photonics, IBM and colleagues at Columbia University announced the demonstration of a mid-infrared (mid-IR) optical parametric amplifier, which has been designed and built using ultra-compact silicon nanophotonic waveguides. An amplifier of this type can be applied to boost the intensity of very weak information-carrying optical signals. However, unlike the glass-fiber-based optical amplifiers which are commonly used in today’s near-IR fiber optic telecommunication systems, IBM’s new amplifier is constructed using chip-scale ultra-compact silicon nanophotonic waveguides. The silicon amplifier is specifically designed to operate at longer wavelengths in the mid-IR spectrum, and can boost signals over a broad wavelength range from 2050-2250 nm, to as much as 400-times their original strength.

The capabilities of this device can potentially be applied to improve the integrity of optical signals relevant to a wide range of mid-IR applications, including sensors for monitoring of pollutant concentrations within the environment, instruments for high-sensitivity medical diagnostics and imaging, and point-to-point free-space optical communication.

Our work illustrates that the silicon nanophotonic tool set, developed at IBM for on-chip optical interconnects, can be leveraged to enable an entirely new class of technologies tailored to the mid-IR spectrum. By utilizing IBM’s established wafer-scale fabrication processes for silicon nanophotonics, it is possible to envision the development of chip-scale, low-cost, multi-function photonic integrated circuits targeting these mid-IR applications.


2. How is this advancement related to IBM’s Silicon On-Chip Optical Interconnects Project?


IBM has a long-term commitment to developing Silicon Nanophotonics for on-chip optical interconnects. This area is viewed as a critical technology for enablement of next-generation supercomputers with exa-scale performance. The silicon mid-IR amplifier advancement is part of an exploratory scientific effort, specifically targeting an entirely new and different set of mid-IR technological applications, while leveraging the existing Silicon Nanophotonics know-how.


3. How does it work?


Typical semiconductor optical amplifiers use III-V semiconductor materials having a direct bandgap, for the large efficiency with which they are able to emit and amplify light. However, silicon is generally not a good semiconductor material for an amplifier application, because of the indirect nature of its bandgap. In contrast, our mid-IR silicon optical amplifier works by making use of a nonlinear optical process called “four-wave mixing,” which has been specifically designed to have high efficiency within our silicon nanophotonic waveguides. In the four-wave mixing process, a strong “pump” beam traveling inside the silicon waveguide amplifier interacts with a second “signal” beam, resulting in an exchange of energy between beams, in addition to generation of new frequency components. A useful analogy is to think about the “pump” and “signal” laser beams as different “primary colors.” The process of four-wave mixing then allows you to combine these primary tones to generate an entirely new palette of color within the silicon waveguide. Under the appropriate conditions, this very same process can also be used to “boost,” or amplify, the intensity of a broad spectrum of optical signals traveling within the silicon waveguide, as was demonstrated in our work.

Moreover, this large palette of color combinations produced by four-wave mixing can also be split up and subdivided by a number of integrated filters on the silicon chip, to be used as needed for mid-IR applications including environmental monitoring, medical diagnostics, and free-space optical communication. Note that in this case, the range of “colors” present in the light beams lies within the mid-IR spectrum, at wavelengths in the range from 2-2.5 m. These wavelengths are significantly longer than the deepest shades of red color typically visible to the human eye.


5. When will this technology be available to the general public?


While demonstration of the ultra-compact silicon mid-IR OPA represents a significant step toward development of an integrated photonic platform for mid-IR applications, there are certainly a number of considerable challenges to overcome along the road ahead. At the moment, this is an exploratory project aimed at proving the fundamental operation of the necessary devices and technologies, with potential commercial applications being more than 5 years out.


6. What are the next steps?


In addition to further improving the amount of parametric gain we can obtain on the chip, we also plan to investigate ways of applying the large on-chip gain we’ve already demonstrated to construct a related type of silicon device, a mid-IR optical parametric oscillator (OPO). An OPO would involve using an integrated on-chip resonant cavity, micro-fabricated along with the optical amplifier, to provide optical feedback and enhancement of the pump laser. When combined with optical gain, the addition of the on-chip resonator would produce a very broadband multi-wavelength mid-IR laser source, potentially spanning hundreds of nanometers of mid-IR spectrum. This type of source would serve as an integral and flexible component within integrated photonic systems addressing the above-mentioned mid-IR applications.