Northwestern scientists develop first liquid nanolaser

northwestern-scientists-develop-first-liquid-nanolaser

Scientists from the Northwestern University have developed the first liquid nanoscale laser. And it’s tunable in real time, meaning you can quickly and simply produce different colors, a unique and useful feature. The technology could lead to practical applications, such as a new form of a “lab on a chip” for medical diagnostics.

To understand the concept, imagine a laser pointer whose color can be changed simply by changing the liquid inside it, instead of needing a different laser pointer for every desired color.

In addition to changing color in real time, the liquid nanolaser has additional advantages over other nanolasers: it is simple to make, inexpensive to produce and operates at room temperature.

Nanoscopic lasers – first demonstrated in 2009 – are only found in research labs today. They are, however, of great interest for advances in technology and for military applications.

“Our study allows us to think about new laser designs and what could be possible if they could actually be made,” said Teri W. Odom, who led the research. “My lab likes to go after new materials, new structures and new ways of putting them together to achieve things not yet imagined. We believe this work represents a conceptual and practical engineering advance for on-demand, reversible control of light from nanoscopic sources.”

Odom is Board of Lady Managers of the Columbian Exposition Professor of Chemistry in the Weinberg College of Arts and Sciences.

The findings were published last week by the journal Nature Communications.

The liquid nanolaser in this study is not a laser pointer but a laser device on a chip, Odom explained. The laser’s color can be changed in real time when the liquid dye in the microfluidic channel above the laser’s cavity is changed.

The laser’s cavity is made up of an array of reflective gold nanoparticles, where the light is concentrated around each nanoparticle and then amplified. (In contrast to conventional laser cavities, no mirrors are required for the light to bounce back and forth.) Notably, as the laser color is tuned, the nanoparticle cavity stays fixed and does not change; only the liquid gain around the nanoparticles changes.

The main advantages of very small lasers are:

• They can be used as on-chip light sources for optoelectronic integrated circuits;

• They can be used in optical data storage and lithography;

• They can operate reliably at one wavelength; and

• They should be able to operate much faster than conventional lasers because they are made from metals.

Some technical background

Plasmon lasers are promising nanoscale coherent sources of optical fields because they support ultra-small sizes and show ultra-fast dynamics. Although plasmon lasers have been demonstrated at different spectral ranges, from the ultraviolet to near-infrared, a systematic approach to manipulate the lasing emission wavelength in real time has not been possible.

The main limitation is that only solid gain materials have been used in previous work on plasmon nanolasers; hence, fixed wavelengths were shown because solid materials cannot easily be modified. Odom’s research team has found a way to integrate liquid gain materials with gold nanoparticle arrays to achieve nanoscale plasmon lasing that can be tuned dynamical, reversibly and in real time.

The use of liquid gain materials has two significant benefits:

• The organic dye molecules can be readily dissolved in solvents with different refractive indices. Thus, the dielectric environment around the nanoparticle arrays can be tuned, which also tunes the lasing wavelength.

• The liquid form of gain materials enables the fluid to be manipulated within a microfluidic channel. Thus, dynamic tuning of the lasing emission is possible simply by flowing liquid with different refractive indices. Moreover, as an added benefit of the liquid environment, the lasing-on-chip devices can show long-term stability because the gain molecules can be constantly refreshed.

These nanoscale lasers can be mass-produced with emission wavelengths over the entire gain bandwidth of the dye. Thus, the same fixed nanocavity structure (the same gold nanoparticle array) can exhibit lasing wavelengths that can be tuned over 50 nanometers, from 860 to 910 nanometers, simply by changing the solvent the dye is dissolved in.

The National Science Foundation (grants DMR-1306514 and DMR-1121262) supported the research.

Source: Northwestern University

Reference: 

  • "Real-time tunable lasing from plasmonic nanocavity arrays" –  Ankun Yang, Thang B. Hoang, Montacer Dridi, Claire Deeb, Maiken H. Mikkelsen, George C. Schatz & Teri W. Odom – Nature Communications 6, Article number: 6939 – doi:10.1038/ncomms7939

Featured image credit: Northwestern University/Nature

If you value what we do here, create your ad-free account and support our journalism.

Share:


Your support makes a difference

Dear valued reader,

We hope that our website has been a valuable resource for you.

The reality is that it takes a lot of time, effort, and resources to maintain and grow this website. We rely on the support of readers like you to keep providing high-quality content.

If you have found our website to be helpful, please consider making a contribution to help us continue to bring you the information you need. Your support means the world to us and helps us to keep doing what we love.

Support us by choosing your support level – Silver, Gold or Platinum. Other support options include Patreon pledges and sending us a one-off payment using PayPal.

Thank you for your consideration. Your support is greatly appreciated.

Sincerely,
Teo Blašković

$5 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$50 /year

$10 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$100 /year

$25 /month

  • Ad-free account
  • Clean user interface and fast browsing
  • Direct communication with us via chat and email
  • Suggest new features, content and applications
  • Early access to new apps and features

$200 /year

You can also support us on Patreon

support us on patreon

or by sending us a one-off payment using PayPal:


Commenting rules and guidelines

We value the thoughts and opinions of our readers and welcome healthy discussions on our website. In order to maintain a respectful and positive community, we ask that all commenters follow these rules:

  • Treat others with kindness and respect.
  • Stay on topic and contribute to the conversation in a meaningful way.
  • Do not use abusive or hateful language.
  • Do not spam or promote unrelated products or services.
  • Do not post any personal information or content that is illegal, obscene, or otherwise inappropriate.

We reserve the right to remove any comments that violate these rules. By commenting on our website, you agree to abide by these guidelines. Thank you for helping to create a positive and welcoming environment for all.

Leave a reply

Your email address will not be published. Required fields are marked *