Deep learning optimized single-pixel LIDAR

Hello all!

The first Seminar of the year will be given by Steven Johnson on the topic of Deep learning optimized single-pixel LIDAR on 15:00 on  Thursday 13/02/2020 in room 312.

Here is the abstract:

Light detection and ranging (LIDAR) systems have become a key technology for self-driving vehicles, with depth information typically gained through time-of-flight measurements. Single-pixel imaging can take pictures without using a pixelated array like a CCD. The single-pixel imaging also allows a choice of sampling basis, an optimised sampling basis was developed via deep learning to speed up the measurement process. By combining LIDAR with the optimised single-pixel imaging technique a better depth and intensity measurement can be made when using photon-counting detectors.

Snacks will be provided in the common room afterwards.

Cheers,
Kyle

The last Optical Sciences Seminars of the year

Hello everyone!

With the next week being the last week before the holidays, why not get out of the lab with two interesting seminars, to be followed with festive treats.

On Tuesday, Gregory Chaplain from Imperial College London is visiting University of Glasgow and will give a seminar titled "Good Vibrations: Controlling Waves, from Elasticity to Electromagnetism". Abstract

On Thursday, Rachel Offer of the Optics Group will give a talk titled "Atomic vapour wave mixing and structured light". Abstract

Gregory will give his talk at 14:00 on 17/12/19 in Kelvin 222.

Rachel will give her talk at 15:00 on 19/12/19 in Kelvin 222.

Festive treats will be provided in the common room afterwards where on or off topic discussion can continue over some festive treats!

I hope to see you all there,
Kyle

Quantum Gyroscope: using Hong-Ou-Mandel interference to test the role of relativity in quantum mechanics

Hello all!

This weeks Optical Sciences Seminar will be given by Sara Restuccia. The talk is titled "Quantum Gyroscope: using Hong-Ou-Mandel interference to test the role of relativity in quantum mechanics", and will be given on 7th November at 15:00 in room 222.

Abstract:

We test the role of relativity in quantum mechanics by studying the behaviour of entangled photons in a noninertial reference frame, in our experiment a rotating platform. Hence, we set up a fibre gyroscope, where two counterpropagating waves interfere at a common beamsplitter. Classically, this results in interference fringes which shift when the interferometer is rotated, in a phenomenon known as the Sagnac effect. In a nonclassical system, the interference of two entangled photons at a beamsplitter produces a phenomenon known as the Hong-Ou-Mandel effect (HOM). Here, a characteristic HOM dip in the coincidences of the detected photons is observed when the photons are indistinguishable. By setting our HOM on a rotating platform we were able to measure a shift in the position of the HOM dip as a function of the rotation speed. This relative delay in the photons arrival is equivalent to the classical Sagnac effect with the sole difference being that while in the classical set-up the rotation motion induces a change in the interference of the two beams, in the quantum set-up the change is in the quantum interference of the two photons.


Snacks will be provided in the common room after the talk!
Kyle

Implementing LiDAR spoofing using single Pixel Imaging and Optical delay lines

Hello all!

This weeks Optical Sciences Seminar will be given by Ahmed Elmubarak. The talk is titled "Implementing LiDAR spoofing using single Pixel Imaging and Optical delay lines", and will be given on 26th September at 15:30 in room 222. Please make note of the change of time and room. This is due to demonstrating schedules and the SUPA lecture series has started for this semester.

Abstract:

LIDAR is an indispensable sensor technology – along with other sensors- for autonomous vehicles which operates by scanning a pulsed light source and measuring the time of arrival of reflected light on a detector, whereupon the distance to objects is calculated from the time-of-flight (Δd = cΔt/2). We’ll explore the idea of spoofing A LiDAR system (in this case built using Single Pixel Imaging camera) into seeing simulated 3D virtual reality scenes. This technology, once realized can be used for testing integrated LiDAR system in autonomous vehicles without having to hack into the car system. The talk will have an introduction to Single Pixel Imaging and LiDAR technology.


Snacks will be provided in the brand new common room after the talk!
Kyle

From atomic magnetometry to image memory

HI all,

The second Optics Group Optical Sciences Seminar will be given by Francesco Castellucci. The talk is titled "From atomic magnetometry to image memory", and will be given on 18th July at 15:00 in Kelvin Room 222.

Abstract:

The spherical orientation of a magnetic field can be seen through the interaction between light with Orbital Angular Momentum (OAM) and a cold atomic cloud. Applying two vector vortex beams to a cloud of atoms, the azimuth angle of the magnetic field is seen in the linear rotation of the transmitted pattern, and the inclination is reflected in a fracturing of the observed image. Using a similar setup it should be possible for any kind of complex beam to be stored in the magnetic dipoles of the atoms.

Unfortunately I cannot make it. However, Sara Restuccia will host the Seminar and provide snacks in the common room afterwards.

Kyle

Bell inequality in full field images of spontaneous parametric down-conversion

Hello Everyone!

I hope you are having a great summer so far. This weeks Optical Sciences Seminar will be given by Paul-Antoine Moreau of the Optics Group. The talk is titled "Bell inequality in full field images of spontaneous parametric down-conversion", and will be given on 4th July at 15:00 in Kelvin Room 312.

Abstract:

We use an imaging setup based on heralded imaging to test a Bell-CHSH inequality within images. Based on a single full-field image accumulated by summing camera frames we find that the Bell inequality is violated.

Loophole free demonstrations of Bell non-locality have been performed recently. But testing Bell inequalities in new domains remains an objective of importance given the very pivotal role that Bell non-locality could play within the emergence of quantum technologies. We report on an attempt at performing such a demonstration in the context of quantum imaging.

With the common room still out of action snacks will be provided outside Room 312 when the talk finishes.

See you there!
Kyle

Hi all, 

The next Optical Sciences seminar will be given by Neel Mackinnon from the Quantum Theory group at 3pm on Thursday 9th May in 222. Neel will be presenting the following: 

Title: Electromagnetic Helicity within a Chiral Medium

Abstract: The electromagnetic helicity is a locally conserved quantity of the free electromagnetic field which, in a sense, describes the “handedness” of the field. The name “helicity” can be justified by the fact that the total helicity of an electromagnetic field, integrated over all space, is proportional to the difference in the number of left- and right-handed circularly polarised photons in the field. The concept of helicity can also be made meaningful in presence of matter – in this case it is no longer conserved, but charges and currents may act as sources or sinks of helicity. The definition of helicity can then be very straightforwardly extended to apply within dielectrics. 

However, this straightforward extension runs into difficulties if the dielectric material is chiral (that is, if it can exhibit optical rotation). This talk will introduce some of the features of electromagnetic helicity, and describe a proposed modification to the definition of the helicity density within a chiral medium.

The talk will last around 20 minutes, followed by coffee and biscuits in the common room. 

Hope to see you there,

Frances