Optical Simulation of a Quantum Particle Living on a Surface of a Tetrahedron

Hello all!

The first of the Optics Group's Seminars will be by Jakub Belin who will give a talk titled "Optical Simulation of a Quantum Particle Living on a Surface of a Tetrahedron".

The talk will take place on 28th February at 16:00 in Kelvin 222.

Abstract:

We analyze propagation of waves on the surface of the simplest Platonic solid, the regular tetrahedron.  We find the time evolution of a quantum particle confined to such a surface is completely analogous to the diffraction pattern from a certain grating profile, and can therefore be investigated in a simple diffraction experiment.  The quantum particle exhibits perfect quantum state revivals, which translate into the fractional Talbot effect in the equivalent diffraction experiment.  We present the results of such an experiment and compare them with numerical simulations.

As usual, snacks will be provided afterwards in the common room. I hope to see you there!

Cheers,
Kyle

Skyrmion structure in vector beams

Hi everyone, 

The first talk of the year will be given on Thursday 17th January by Scarlett Gao from the Quantum Theory group on the following: 

Skyrmion structure in vector beams
Vector beams have both a spatially varying amplitude and polarization, for light, or spin direction for electrons.  Associated with these we find a topological feature, the skyrmion number, that it is robust against any deformation during propagation. The simplest way to map out this feature is to use the associated skyrmion field.  This is a transverse or divergenceless field and so has neither sources nor sinks.  Mapping out the skyrmion field for these beams reveals constraints on the manner in which vector beams can be manipulated.

The talk will begin at 4pm in lecture theatre 312 and will last around 20 minutes. This will be followed by refreshments in the common room. 

Hope to see you there!

Frances 

Quantum eavesdropping strategies

Hi everyone,

The last talk of the year will be given by Kieran Flatt from the Quantum Theory group, on quantum eavesdropping strategies.

Abstract:
Quantum key distribution is a method for sharing cryptographic keys and which uses the active nature of quantum measurements to flag eavesdropping to the legitimate users. I'll present two schemes, the well-known BB84 and lesser explored PCB00, and explain what the best eavesdropping strategies are in each case.

The talk will be on Thursday 6th December at the usual time of 4pm in 257.

Join us afterwards in the common room for some mulled wine and suitably festive treats! 

Frances 

Compressive light-sheet microscopy by Chiara Garbellotto

Hello everyone,

Chiara will be our next presenter at the optical sciences seminars. She will talk about her work on light-sheet microscopy: "I'll summarise what I've done so far during my PhD and talk about what I'm working on at the moment (tiling light-sheet, z-compressed light-sheet), hoping to get some inspiration/suggestions/advice."

Check out a 3 minute thesis winning video by Chiara for a very cartoon-y intro to light-sheet microscopy  https://www.youtube.com/watch?v=7WM8D_A4leY

Please note that there is a change in venue and time.

Date: Thursday 22nd November
Time: 16:30
Venue:  Room 255A SUPA VC room

We will be having some mulled wine and mince pies after the talk in the common room. See you all there! :)


Cheers,
Pavi.

Computational imaging in infrared domain using multiple cameras and more..

Hello everyone!


It's Imaging concepts group's turn to present this week. Dr. Miguel Preciado will be presenting his research on building low-cost infrared camera arrays for enhanced capabilities such as Integral (light-field) imaging, Pixel super-resolution, and multi-spectral imaging. Click here for more details on the topic.


Date: Thursday 8th November
Time: 16:00
Venue:  Room 257

Snacks will be provided in the common room after the seminar.

Cheers,
Pavi.

Orbital Angular Momentum Reversal due to Extreme Doppler Shifts - Graham Gibson

Hello everyone!

Continuing the Optics Group's turn at hosting seminars will be Graham Gibson. The talk, titled Orbital Angular Momentum Reversal due to Extreme Doppler Shifts, will take place on Thursday 25th October at 16:00 in Room 257. The abstract is as follows:

The linear Doppler shift is familiar to everyone as the change in the observed frequency of an ambulance siren as it passes by. A less well known form is the rotational Doppler shift which is proportional to the relative rotation rate between source and observer, multiplied by the angular momentum carried by the beam. Using an acoustic source of orbital angular momentum we can demonstrate an extreme Doppler shift that is larger than the rest-frame frequency, resulting in the observed frequency becoming negative in the case of a red shift. The emergence of negative frequencies in physical systems is often accompanied by intriguing consequences. For the linear case this is associated with a time reversal of the received signal. For the rotational case it is associated with a handedness reversal of the detected orbital angular momentum.

Snacks will be provided in the common room after the seminar and once again Curler's Rest has been nominated as a pub where discussion can continue after work.

Kyle

The applications of single-pixel imaging - Steven Johnson & Yiwei Zhang

Hello everyone!

This weeks Seminar will be given by Steven Johnson & Yiwei Zhang on The applications of single-pixel imaging. The talk will take place on Thursday 11th October at 16:00 in Room 257. The abstract is as follows:

Single-pixel imaging enables the photography of phenomena that would be impossible with a traditional camera. Most images are captured with pixelated-arrays such as a CCD or CMOS sensors; whereas single-element detectors can be manufactured to be sensitive to unusual wavelengths, outside the visible spectrum, or have very fast response times. By using a detector with high temporal resolution, events occurring on the order of nanoseconds can be imaged. Using a digital micro-mirror device and a pulsed laser we have applied single-pixel imaging methods to many applications, these include: 3D videos of a scene, imaging the light-in-flight, fluorescence lifetime imaging and duel-band astronomy.

Snacks will be provided in the common room after the seminar and once again Curler's Rest has been nominated as a pub where discussion can continue after work. Turnout was great two weeks ago so I look forward to seeing people there again!

Kyle.