Scientists from the Light-Matter Interactions Unit, led by Professor Síle Nic Chormaic at the Okinawa Institute of Science and Technology Graduate University (OIST), have developed a new technique to fabricate glass microlasers and tune them using compressed air. The new technique, published in Scientific Reports, could pave the way for the simple serial production of glass microlasers and could be used in a wide range of applications, such as optical communications, chemical or biosensing.
Microlasers are tiny optical devices a few tens of micrometres in diameter that are able to create intense light with only one colour or wavelength. OIST researchers found a new method to fabricate a special type of glass microlaser, called whispering gallery microlasers.
Whispering gallery microlasers are doughnut-shaped or spherical devices produced from glass doped with rare earth elements, such as erbium or ytterbium (Er or Yb). Inside the microlasers, light is reflected over and over creating a 10-100 metre long optical path within a tiny device that's the size of a grain of sand.
Taking advantage of the different melting temperatures of silica and Er or Yb doped phosphate glass, OIST scientists have devised a new way to produce microlasers via glass wetting, or glass-on-glass fabrication. In this new technique, a strand of Er or Yb doped phosphate glass is melted and allowed to flow around a hollow capillary of silica.
This is possible because of the different melting temperatures of silica and phosphate glass at 1500°C and 500°C, respectively. This technique produces bottle-shaped microlasers, which are 170 micrometres in diameter. The bottle-shape can then be modified to become a thin coating of only a few micrometres in diameter around the capillary.
While fabricating doped glass microlasers using traditional methods can be tedious, with each individual sphere being attached to a glass strand, this glass wetting technique allows scientists to make any number of microlasers quickly and in series.
This technique also facilitates a new way of tuning the wavelength or colour of light emitted by the microlasers. The tuning is achieved by a combination of pressure and temperature. Compressed gas passed through the capillary cools the walls of the hollow structure. This cooling effect makes the diameter of the microlaser contract, which changes the laser output wavelength.
Microlasers prepared with this new technique were used to measure the air flow in microfluidic devices and have been shown to be more sensitive than commercial electronic flow sensors, as well as 10,000 times smaller.
"We wanted the ability to tune micro-scale lasers without increasing the size and the complexity of the device and keeping high quality," points out Dr Jonathan Ward, the first author of this study. "This could be a step towards the quick and easy fabrication of smaller devices for biosensing and optical communications."
Kaoru Natori | EurekAlert!
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering