Postdoc researcher Integrated light modulators for atomic and ionic quantum computing
What you will do
Over the past years, a second quantum revolution has emerged because researchers gained unprecedented control over nature’s best qubit, the atom. In atomic and ionic quantum computing, qubit gates are implemented with a set of laser beams that span from the UV to near-IR. These laser beams have to be modulated with speeds above 1 MHz (up to 100s of MHz to implement optimal qubit control pulses), with extreme light extinction ratios (above 50 dB to minimize gate errors), and without interfering background light (i.e. very clear laser beams without any sidelobes). In such systems, the problem is therefore not so much the qubit scaling, but the scaling of the photonic control system.
Photonic integrated circuits (PICs) are a promising route to integrate many optical functionalities with performance specs that surpass their bulk counterparts on a single chip, thereby providing scalability and cost reduction as additional advantages. Traditionally, most PICs were developed in silicon due to the dense integration possibilities and the fact that devices could be fabricated using technologies from the CMOS electronics world, allowing high-quality, and repeatable fabrication processes. Silicon is however not transparent for visible wavelengths and hence cannot be use for atomic and ionic control. Silicon nitride (SiN) on the other hand is transparent in the relevant wavelength range, but suffers from one major drawback: it is very hard to modulate the phase of the light signal in a fast and efficient way.
In addition to the difficulties of making efficient and fast phase-shifters, it is moreover important to note that the amplitude modulators and beam scanners using these phase shifters are having performance issues themselves. Amplitude modulators rely on interference to switch the light ON/OFF, so they are very sensitive to fabrication imperfections (e.g. waveguide roughness which leads to phase errors) and environmental perturbations (e.g. local temperature changes on the chip). As such there is always need for precise feedback control. In addition, interference-based amplitude modulators typically have low extinction ratios (about 20 dB), requiring a cascading to achieve 50 dB, which in turn will increase optical excess losses. Optical-phased arrays, commonly used for beam scanning, on the other hand suffer from the existence of sidelobes, creating unwanted background light and optical excess loss.
It is therefore clear that the traditional approaches commonly used in integrated photonics cannot be readily transferred and novel integrated architectures must be investigated. You will be responsible for the experimental investigation of a novel patent pending architecture for efficient and fast modulation of visible wavelengths. You will be leading the build of a new characterization setup and perform advanced optical measurements on devices fabricated in imec’s cleanroom. While the position is mainly geared towards experimental efforts, you will also be involved in the design of new and improved geometries using feedback from the measurements.
What we do for you
We offer you the opportunity to join one of the world’s premier research centers in nanotechnology at its headquarters in Leuven, Belgium. With your talent, passion and expertise, you’ll become part of a team that makes the impossible possible. Together, we shape the technology that will determine the society of tomorrow.
We are committed to being an inclusive employer and proud of our open, multicultural, and informal working environment with ample possibilities to take initiative and show responsibility. We commit to supporting and guiding you in this process; not only with words but also with tangible actions. Through imec.academy, 'our corporate university', we actively invest in your development to further your technical and personal growth.
We are aware that your valuable contribution makes imec a top player in its field. Your energy and commitment are therefore appreciated by means of a 1 year contract with a market appropriate salary and many fringe benefits.
Who you are
As an ideal candidate you:
- Have a PhD in photonics engineering (or equivalent through experience)
- Have substantial experimental experience in photonics, in particular building of fiber- and free-space optical setups and high-speed RF measurements (VNA, spectral analysis).
- Have a working knowledge of Python / Python interfacing with lab equipment
- Have a working knowledge of electromagnetic solvers (Lumerical FDTD/MODE, COMSOL)
- Are independent and critically thinking in performing tasks, but able to collaborate in a team
- Have strong English communication skills
- Knowledge of semiconductor manufacturing processes for photonics is a plus but not a requirement
- Knowledge of basic quantum mechanics is a plus but not a requirement