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Nanomaterials

AIPT’s Nanomaterials Photonics Group focuses on development of functional carbon nanomaterials with strong optical properties for ultra-short pulse lasers and sensor applications. 


We operate:

  • Clean Room facilities for nanomaterials processing and functionalization 
  • Auto-drop platform for nanomaterials ink-jet printing 
  • Advanced optical spectroscopy laboratory for characterisation of nanomaterials optical properties from UV to mid IR spectral range Fibre laser laboratory for development of mode-locked fibre lasers 

Our recent results include:

  • First identification of the carbon nanotube (CNT) ‘salting-out’ effect in organic solvents. 
  • Development of polymethinedye fluorescent probe for rapid recognition of CNTs. 
  • First experimental demonstration in laser physics of spiral attractors, achieved in fibre lasers mode-locked by CNT. 
  • High power generation of sub-ps pulses in Tm doped fibre laser with CNT mode locker.
As grown nanomaterials typically have a wide distribution in size, surface and conductive properties. They also tend to form aggregates and show a relatively poor stability in liquid media. Nanomaterials photonics group is working toward development of stable dispersion of the prepared nanomaterials in aqueous and organic solvents via non-covalent approach, which typically does not affect their optical properties. We use different surfactants or polymers to create the non-covalent forces, including electrostatic interaction, hydrogen bonding and hydrophobic interaction. This stabilizes individual nanoparticles, at the same time inhibiting their agglomeration in liquids. Then, we sort the nanomaterials by their diameters, using density gradient centrifugation technique. The resulting dispersion is applicable for photonic nanocomposites preparation or as a nano-ink for deposition on the optical parts with advanced auto-drop (Microdrop Technologies GmbH) ink-jet printing platform. 


The following applications designed and developed with functionalise nanomaterials in our group: 

  • Polymer and microchannel saturable absorbers for mode-locked fibre laser generating between 1000 and 1900 nm. 
  • Functional carbon nanomaterials coatings for plasmonic gas sensors.

 

This NATO SPS  project addresses the problem of rapid portable sensors for the detection of dangerous environment polluters. In the frame of the project we develop a sensor system for the spectroscopic detection of three major types of the polluters: 
  • Ammonia, aliphatic primary and secondary amines. 
  • Heavy metals (mercury, lead, zinc, cadmium). 
  • Hydrogen sulphide and mercaptanes. 
  • Carbon nanotubes, which are toxic, and will be potential industrial polluter in the near future. 

The optical spectroscopy methods have been proved as sensitive tools for such detection. However the selectivity and sensitivity of such techniques require a further improvement. Here, we develop new detection method combining the chemical synthesis of sensor/ probe molecules, development of optical spectroscopy techniques for their detection and finally fabrication the sensor device by using novel photonics micro-fabrication tools.

We work on development of CNT and Graphene composites for creation of novel fibre/waveguide lasers with emission in the broad spectral range covering telecom and sensor applications. Compact mode-locked fibre lasers will be key components for highly sensitive optical techniques in greenhouse gas monitoring, bio-medical sensing. 


The overall research objectives for the TeLaSens project are: 


  • Optimization of Carbon NanoTube (CNT) saturable absorber device using theoretical modelling and experimental physical-chemistry methods.
  • Design and development of new CNT based saturable absorber devices and comparison of them to the Semiconductor Saturable Absorption Mirrors (SESAMs). 
  • Design and development of new fibres for laser sources. 
  • Design and theoretical modelling of new laser cavities. 
  • Fabrication and testing of new ultra-short pulse lasers. 
  • Development of laser based sensor systems. We have recently demonstrated both advanced saturable absorption devices made of CNT and graphene, Yt, Er and Tm doped mode-locked fibre lasers with sub-ps pulse generation regimes.