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!
Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz
New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
20.02.2017 | Materials Sciences
20.02.2017 | Health and Medicine
20.02.2017 | Health and Medicine