Pumping a nanoparticle to lase at low power

December 01, 2020

Lasers are used in a range of everyday devices, harnessing the power of light molecules, photons, - lined up to form highly concentrated beams of light - to perform now common tasks such as scanning barcodes and removing tattoos.

As biosensing and bio-imaging research seeks to look deep inside tissue to the intracellular level miniaturising laser devices poses significant challenges for these nanoscale biological applications. In new research, published in Nature Communications, scientists demonstrate how the earlier promising concept of a microcavity laser can produce an energy-saving and user-safe laser emissions requiring low pump power.

Corresponding author Dr Jiajia Zhou, from the University of Technology Sydney (UTS), said that normally low pump power is insufficient to make nanoparticles to lase but the team was able to "control the luminescent emitters within every single nanoparticle to interact with each other so that the electrons can accumulate at specific energy levels".

"This means that even at a very low power pump the nanoparticles will lase, in fact we demonstrated a two-order of magnitude lower pumping threshold compared to what is usually achieved," she said.

The research team also had to engineer the binding surface of the nanoparticle matrix to form a cavity surface with a uniform single layer.

Dr Zhou said that potentially the Near Infra Red (NIR) microcavity laser can be embedded in thick tissues, single cells, and to sense the environmental indicators such as temperature, pH, and refractive index.

"Monitoring the change of these indicators can tell us the health status of the tissues or cells, which sits in the scope of early-stage disease detection, "she said.

Senior author, director of UTS Institute for Biomedical Materials & Devices Professor Dayong Jin, said this discovery held great promise for biological applications.

''I think this is definitely a step forward to realising the dream that just as we use a laser pointer on a powerpoint slide, we could point a tiny device inside a cell, and illuminate an area of interest inside the compartments of a cell.

"Lowering the requirement for the pump power means less tissue damage as the laser penetrates the sample. Also, in this case the laser emission is as sharp as a line, it can sense the indicators more accurately by avoiding the undesired interference which frequently happens in spontaneous fluorescence-based sensing," he said.

"It's not science fiction. We've demonstrated a single nanoparticle, which is smaller than an intracellular compartment, can act like a laser, and at low power but it can still emit a sharp signal. In otherwords a 'laser pointer' small enough to get inside a cancer cell, and illuminate to stop the engine of that cancer cell," Professor Jin, who is also the director of UTS-SUStech Joint Research Centre, said.
-end-


University of Technology Sydney

Related Laser Articles from Brightsurf:

Laser technology: New trick for infrared laser pulses
For a long time, scientists have been looking for simple methods to produce infrared laser pulses.

Sensors get a laser shape up
Laser writing breathes life into high-performance sensing platforms.

Laser-powered nanomotors chart their own course
The University of Tokyo introduced a system of gold nanorods that acts like a tiny light-driven motor, with its direction of motion is determined by the orientation of the motors.

What laser color do you like?
Researchers at the National Institute of Standards and Technology (NIST) and the University of Maryland have developed a microchip technology that can convert invisible near-infrared laser light into any one of a panoply of visible laser colors, including red, orange, yellow and green.

Laser technology: The Turbulence and the Comb
While the light of an ordinary laser only has one single, well-defined wavelength, a so-called ''frequency comb'' consists of different light frequencies, which are precisely arranged at regular distances, much like the teeth of a comb.

A laser for penetrating waves
The 'Landau-level laser' is an exciting concept for an unusual radiation source.

Laser light detects tumors
A team of researchers from Jena presents a groundbreaking new method for the rapid, gentle and reliable detection of tumors with laser light.

The first laser radio transmitter
For the first time, researchers at Harvard School of Engineering have used a laser as a radio transmitter and receiver, paving the way for towards ultra-high-speed Wi-Fi and new types of hybrid electronic-photonic devices.

The random anti-laser
Scientists at TU Wien have found a way to build the 'opposite' of a laser -- a device that absorbs a specific light wave perfectly.

Laser 'drill' sets a new world record in laser-driven electron acceleration
Combining a first laser pulse to heat up and 'drill' through a plasma, and another to accelerate electrons to incredibly high energies in just tens of centimeters, scientists have nearly doubled the previous record for laser-driven particle acceleration at Berkeley Lab's BELLA Center.

Read More: Laser News and Laser Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.