Cool Method for Making Waveguides
April 28, 2016 | A*STAREstimated reading time: 2 minutes
Silicon-based films that are useful for waveguides have been made at temperatures low enough to be compatible with standard manufacturing processes. A low-temperature method to produce films based on silicon and nitrogen, which can be used to channel light in devices, has been developed by A*STAR researchers.
Silicon is very a familiar material because of its prevalence in electronic devices, and is increasingly being used in optical and electro-optical devices as well. In particular, it is used to guide light along narrow stripes in components known as waveguides. While silicon has many advantages, it suffers from high losses when used in waveguides as a result of nonlinear absorption at the wavelength used for telecommunications (1,550 nanometers).
One way to reduce these losses is to incorporate nitrogen atoms to produce so-called silicon-rich nitride ― a material whose nitrogen content is intermediate between pure silicon and silicon nitride. But, the usual techniques for making silicon-rich nitride require high temperatures, which renders the process incompatible with the standard technology used for constructing integrated circuits.
Now, Doris Ng at the A*STAR Data Storage Institute and co-workers have discovered a way to make silicon-rich nitride films (see image) at temperatures as low as 250 degrees Celsius, which is much lower than the temperatures usually used to produce the material. They used a plasma ― a gas that has been energized to the point that electrons have been stripped from its molecules ― to deposit a tailored mixture of silicon and nitrogen atoms onto a substrate.
By changing the process parameters, the researchers were able to vary the refractive index of the films. Under certain conditions, they were able to achieve a high refractive index of 3.08 at the telecommunication wavelength. This refractive index is high enough to make it suitable for use in waveguides, but not high enough to cause detrimental nonlinear effects.
The team demonstrated the potential of their films by making waveguides from them. “The waveguide we made using the silicon-rich nitride with the highest refractive index exhibits very good nonlinear performance,” says Doris.
The study heralds the beginning of a fruitful partnership. “This work is a collaborative project between A*STAR Data Storage Institute and Singapore University of Technology and Design,” notes Ng. “I work on material development, while my collaborator, Dawn Tan, specializes in nonlinear optics. I think it’s the perfect team for our project. We are still at the beginning but have been very encouraged by the results obtained so far.”
The team plans to further optimize the material to reduce losses and hence enhance device performance.
Suggested Items
Europlacer Presents New Range of iineo SMT Placement Machines.
05/01/2024 | EuroplacerFor more than 15 years, the Europlacer iineo placement machines have made their mark on the SMT industry with unique features and unrivalled flexibility. Today, Europlacer announces the launch of the second generation iineo.
Incap US Hosts Annual Food Drive
04/30/2024 | IncapIncap US recently concluded its annual food drive, a tradition aimed at supporting the Greater Washington County Food Bank. This year marked the fourth year of the initiative, and we couldn’t be prouder of the collective effort that was made to its success.
Scanfil Uses Employee Engagement Survey to Improve
04/30/2024 | ScanfilOnce a year Scanfil arranges Employee Engagement Survey (EES) in order to get valuable insight from its employees. In EES all employees are invited to share their opinion, bring ideas for improvements, and contribute to making Scanfil a better place to work.
epoxySet Introduces EO-20E – Versatile, Electrically Conductive Epoxy
04/29/2024 | epoxySetepoxySet produces EPOXIOHM EO-20E an industry established, reliable electrically conductive epoxy designed for solder replacement, chip bonding and other intricate electronic and optoelectronic assemblies. This creamy paste has a an easy to use 1:1 mix ratio with a 48 hour work time.
The Right Approach: I Hear the Train A Comin'
04/25/2024 | Steve Williams -- Column: The Right ApproachTraining is often an afterthought in many organizations, and the longer a company has been in business, the more this seems to apply. Over the past couple of decades, it has been amazing to observe that the biggest offenders of this are the companies that overuse the sound bite, “Our most important assets are our people.” When you dig into the process and peel back the onion, their commitment to training is not commensurate with that statement.