Microfab

Laser microfabrication research facility

                            Nanofab

The Dynamic Optics and Photonics Group hosts an advanced adaptive laser fabrication system. An ultrashort (femtosecond) pulsed laser may be used to create a variety of structures with 3D resolution inside transparent materials such as glass, diamond, lithium niobate and polymer films. The system is also compatible with a large range of surface structuring tasks on both transparent and opaque materials. Adaptive optical elements incorporated in the laser beam path allow adaptive aberration correction and dynamic parallelisation, to speed up fabrication times while maintaining a high level of accuracy. Feature sizes from tens of nanometres up to tens of micrometres are possible over areas of several square mm.


The adaptive laser machining system has been established as a small research facility. This enables us to open up our fabrication system to interested parties from other research groups and industry to work together on a variety of applications. These may range from precision fabrication tasks to more advanced projects as part of broader research applications. Examples of fabrication tasks recently undertaken are shown below. 

 

        
Pores etched through a glass coverslip, both oblique (left and centre images) and perpendicular to the surface. The pore size varies from 10um up to 50um and can be controlled on either side of the coverslip allowing a tapered channel.


    
3D photonic waveguides laser-written in fused silica (left image above is a plan view of a waveguide while the centre image reveals the waveguide cross-section) [1]. An example application (right) is a source for heralded single photons via four wave mixing for applications in quantum optics [2].


     
A 3D fluorescence ruler (left) for calibration of scales in the x, y and z axes in a multiphoton microscope (centre and right are fluorescence images of the ruler).

 

The facility also includes optical characterisation systems, including transmission, phase contrast, confocal and harmonic generation (THG/SHG) microscopes. A super-continuum laser source is available for spectral characterisation of photonics structures.  These systems provide three dimensional structural and spectral analysis of photonic structures and other specimens. 

     
Third harmonic generation (THG) images with 3d resolution of a waveguide array (left) and a photonic lantern (middle) in fused silica [3] and (right) combined second and third harmonic signal from a live mouse embryo [4].


The fabrication facility is available for regular use as part of a long term project or can be accessed for bespoke fabrication tasks on an as-required basis.  Please contact for more information or to discuss your particular requirements.

References

[1] Salter et al. Opt. Lett. 37, p.470 (2012)

[2] Spring et al Opt. Express 21, p13522 (2013)

[3] Marshall et al. Opt.Lett. 36, p695 (2011)

[4] Jesacher et al. Opt. Lett. 34, p.3154 (2009)