Quantum computing is one of the most rapidly evolving fields of quantum technologies. It creates strong expectations with respect to technological progress, societal impact, and economic growth. Many of the currently existing quantum computing platforms build upon the availability of lasers and strongly depend on their performance. I will sketch use cases for lasers in quantum computing and discuss the related importance of their optical or technical characteristics as well as the relevance of features like footprint, ease of use, and uptime for the usability of quantum computers.

Light-matter interactions are at the heart of quantum electrodynamics and underpin modern photonic technologies. As we develop means to control the properties of light, matter and their interactions, intriguing new phenomena emerge. We will discuss a few examples ranging from conventional semiconductors to two-dimensional materials and molecular systems.

Dielectric whispering-gallery-mode (WGM) resonators can confine light via total internal reflection. Small perturbations in the local environment usually lead to a frequency shift of the resonator modes directly proportional to the polarizability of the perturbation. Here, we report experimental observations and a theoretical model of strong frequency shifts that can be opposite and even exceed the contribution of the perturbations' polarizability [1]. We also report on a new, independent way of calibrating the prism distance based on Newton’s rings [2] and report on results from ultra-low threshold lasing from a titanium doped sapphire WGM resonator, showing that lasing as well as linewidth narrowing is possible [3]. [1] F. Azeem, …, and H.G.L. Schwefel, Opt. Lett. 46, 2477(2021). [2] J. T. Christensen, …, and H. G. L. Schwefel, arXiv:2208.00667(2022). [3] F. Azeem, …, and H.G.L. Schwefel, Adv. Optical Materials 10, 2102137(2022).

Bulk whispering gallery mode optical resonators like spheres and disks provide a wide range of remarkable optical properties and ultra-high quality factors. In this invited presentation we will show our most recent results on the use of subwavelength metamaterial engineering to couple bulk resonators and integrated Si waveguides. We experimentally achieve up to 99% light coupling efficiency for microspheres and microdisks made of silica, lithium niobate, and calcium fluoride, with diameters between 300 µm and 3.6 mm. These results open promising prospects for the implementation of a new generation of devices combining high-performance bulk resonators and complex Si photonic circuits.

This conference presentation was prepared for SPIE LASE 2023.

While the optical displacement measurement methods have achieved the picometer precision, the latter is considered elusive for the fabrication methods. The Surface Nanoscale Axial Photonics (SNAP) platform allows to fabricate ultralow loss optical microresonators and resonant circuits at the surface of an optical fiber with the remarkable subangstrom precision. Here, we describe recently proposed SNAP optical signal processors, frequency comb generators, microwave photonic filters, and optical sensors with important potential applications which successful realization requires the picometer fabrication precision. We discuss the developed and potential approaches towards the achievement of this challenging goal.

This conference presentation was prepared for SPIE LASE 2023.

We have developed a sensing platform with WGM microlasers and a 2D-dispersion spectrometer. The 2D dispersion is provided by a diffraction grating element in x-axis and a virtual image phase array (VIPA) etalon in y-axis. With a spectral resolution of less than 0.4 pm, the 2D-dispersion spectrometer can detect slight changes of the lasing mode of the microlaser. To demonstrate, we used a polystyrene microsphere as the microlaser and detected the (1) change in refractive index and (2) change in absorption of the medium surrounding the microsphere.

We present an approach to translate and reconfigure SNAP microresonators (SMRs) introduced along a thin-walled hollow silica microcapillary fiber (MCF). First, we demonstrate formation and translation of a train of multiple SMRs induced by a periodic sequence of droplets inside an MCF controlled by air pressure. Next, we reconfigure a permanent SMR introduced at the MCF by a sequence of droplet-induced SMRs controllably translated along the MCF. We believe that the developed approach can become a promising technology for fabrication of reconfigurable low-loss resonant photonic microdevices for optical signal processing applications.

We present the creation of a two-dimensional frequency comb in a single integrated microring resonator through its dual pumping. We demonstrate experimentally and theoretically that dual-pumping allows for the creation of a multi-color soliton with a single group rotation velocity yet multiple phase rotation velocities, yielding multiple soliton eigenfrequencies (i.e. colors). We show that, thanks to the material's nonlinearity, its eigenfrequencies can cascade through four-wave mixing, creating a comb. Because this dimension is orthogonal to the azimuthal mode number dimension, the extracted frequency comb is ultimately a two-dimensional one.

We present the demonstration of elastic collisions between dissipative Kerr solitons at different repetition rates in an integrated microresonator. Their periodic collision results in a periodic inter-exchange of their repetition rate. We observe this phenomenon experimentally, and support it with numerical simulations, with each comb tooth is impacted by the periodic soliton collision, producing an interwoven frequency comb.

Lumped-elements models are commonly used for the analysis of optical frequency combs (OFCs) generated by the parametric modulation of optical microresonators. However, these models do not take into account the spatial modulation distribution (SMD) which is critical for the optimization of the OFCs formation. Here, we consider a parabolic SNAP microresonator (SMR) with harmonically modulated parameters and determine the optimum SMDs for the resonant and adiabatic excitation of the SMR parameters. We suggest that the determined optimal SMD can be experimentally realized using piezoelectric, radiation pressure or linear electro-optical excitation of an SMR.

A full-operated and turn-key clock laser is based on a compact Fabry Perot cavity is developed for the Yb ion clock. The cavity is disk shape with 2 inch diameter and 9.3 mm thickness. Though the compact size, the cavity features vibration insensitive design allowing vibration sensitivity on 10-10/g level. The cavity is installed in a two-layer thermal shield with 10 hours time constant which dramatically suppresses room temperature impact on the cavity. By optimizing the vibration and temperature induced noise, the frequency stability of the laser referenced to this cavity is measured at 2×10-14, mainly limited by the cavity thermal noise.

Laser beam distribution system (LBDS) is an important component at any high-power laser facility. Being a system of mirrors, lenses, and windows, the LBDS can significantly contribute to the laser beam quality degradation at target location. Phase correcting methods are among the few instruments allowing efficient control over the laser spot quality at the application site. We present a simpler solution utilizing only a PSF camera at every site. The PSF optimization is a sensorless modal correction algorithm, where each Legendre polynomial is scanned by the deformable mirror to find the best shape that maximize the PSF sharpness metric.

Transmissive holographic phase masks – i.e., complex phase-structures embedded into the volume of transmissive Bragg gratings – have been shown to possess a high degree of achromatism, uniquely suited for applications utilizing broadband optical-sources. Here we report on the holographic construction of their reflective counterpart in photo-thermo-refractive glass, that simultaneously provide phase incursion for spatial beam-transformation while also operating as narrowband spectral filter. Such an element was implemented in a linear cavity, wavelength-tunable, pulsed dye laser for intracavity beam-shaping.

There have been several studies that consider the optimal form of structured light to pass through aberrating systems, including optical fibre, underwater and a turbulent atmosphere. Here we reveal how to find the true forms of structured light that is impervious to all unitary channels, requiring no adaptive correction or control.