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A key requirement for implementing photonic quantum information networks is the mutual two-photon interference between photons emitted by spatially separated quantum light sources. In order to up-scale such networks, the deterministic fabrication of efficient sources of single and indistinguishable photons is of crucial importance. So far, few experiments reported on two-photon interference (TPI)...
The unavoidable trade-off between resolution and depth of focus (DOF) limits traditional optical imaging. High numerical apertures (NA) enable to increase the resolution, but the associated large angular uncertainty results in a limited range of depths that can be put in sharp focus.
As new generations of diverse polymer materials become available [1], these are being used for an increasingly diverse variety of applications in optics, thereby allowing the realization of entirely new kinds of optical components and systems. Using manufacturing technologies based on MEMS and microsystems, flexible and stretchable materials may be used for the fabrication of components as diverse...
Due to their low-cost, comparable transparency and ease of preparation, polymers are widely used to fabricate various micro- and nano-structures for their applications in micro-optics, micro-fluidics, biomedical systems and so on. And in recent years, femtosecond (fs) laser direct writing process has become a popular tool to fabricate arbitrary three-dimensional (3D) microstructures with nanometer...
Special laser applications ranging from laser material processing, especially micromachining, to medical applications, metrology and spectroscopy demand transform limited ps pulses, often synchronized with a fs source [1]. Here, we present spectral compression of fs pulses inside a regenerative Yb:YAG laser amplifier [2] generated by a mode-locked Yb:KGW oscillator (see Fig. 1a). For spectral shaping...
The need for microoptical elements in various emerging fields such as astrophotonics, nonlinear optics and biomedicine create a demand for a new generation optics that would be lightweight/compact, resilient to harsh environment and easily integrable in other devices. Ultrafast pulses based direct laser writing 3D nanolithography produced microlenses seem as one of the candidates for such applications...
It has been demonstrated that cell adhesion on biocompatible materials is modified when the surface of the material is structured instead of being totally polished [1-3]. An efficient way to texture surfaces is using the foci of a microlens array and a direct write laser technique [4]. Due to the short focal length of the microlens, they can be damaged by expelled material during ablation. In previous...
In the process of the lens production it is extremely important that a total time of measuring the lens thickness, taking into account also the time needed to insert the lens into a system, should be short enough to test the substantial part of the series of products. Currently used methods of measuring lens thickness apply various solutions [1, 2], but none of them offers a fast and cost effective...
We present a compact light-field camera built using a flat-surface gradient index (GRIN) microlenses array. First, we report on the design, fabrication and characterization of a hexagonal array of nanostructured GRIN microlenses suitable to build the camera. The concept of a nanostructured GRIN microlens is based on the effective medium theory. The nanostructured GRIN lens is composed of several hundred...
A good and efficient control of the focus point of a laser beam is essential in many fields such as laser processing and wielding, and confocal microscopy. The most common way of changing the focus position of a beam is to use lenses, usually in the form of a telescope. However, inertia imposes a limit to the frequency at which one can modulate the position of a mechanical element. Other techniques,...
Recently reported optical pulse generators may suffer from large pedestal, large duty cycle, bias drift and/or high-power consumption [1, 2]. Besides, each injected CW laser merely results in pulse on one wavelength using these schemes, which is uneconomical. In this study, we propose a multi-wavelength pedestal-free Gaussian optical pulse generator with low duty cycles on wavelengths twice the number...
Quantum cascade lasers (QCLs) are powerful sources of coherent radiation covering the frequency range from mid-infrared to terahertz. In the terahertz frequency range the active region is normally realized using a GaAs/AlxGa1−xAs semiconductor heterostructure. This material system enables a variable conduction band offset by changing the Al-content in the barrier layers without introducing a significant...
Single mode THz QCLs have already shown their huge potential for metrological grade THz spectroscopy [1, 2] while, on the contrary, continuous-wave multimode broadband operation has only recently been demonstrated [3]. These sources show a comb emission regime with up to 600 GHz spectral coverage. This kind of sources are very promising for metrological-grade applications, such as high precision spectroscopy,...
Ga(As)Sb/GaAs quantum dot broad area lasers (BALs) with an emission wavelength of λ= 930 nm are realised. For suppressing the typical multi-transverse-mode operation of the BALs transverse mode selection filters are monolithically integrated into the laser crystal. Two different approaches are reported, which can both be considered Fourier-optical. Following our spatial-frequency-filter concept with...
We demonstrate miniaturized micro- and nano-optics. Our approach uses femtosecond 3D direct laser writing. Aberration-corrected performance for large angles of incidence is achieved, and our approach solves the common problem of off-axis coma in metasurfaces.
Recent advances in the growth of low loss single crystal diamond [1] coupled with its high Raman gain and high thermal conductivity have led to the material becoming an established Raman laser material. With applications often having to adapt to available laser wavelengths, Raman lasers can be used as a simple means to shift ubiquitous commercial laser sources to the hard to reach but application...
A promising approach towards implementation of large-scale quantum information and communication protocols is a multifunctional photonic quantum information processing system, where a variety of distributed components, such as quantum memories, trapped ions, or photonic quantum gates are coherently interconnected via photonic links. These components may exhibit a vast range of spectro-temporal properties...
Intense ultrafast laser sources in the mid-IR have attracted in the recent years lot of attention in strong-field physics. A possible implementation for such sources relies in: a) the generation of a short IR seed by intra-pulse difference frequency generation (DFG) of a broadband continuum generated in an hollow-core fiber (HCF); b) optical parametric amplification (OPA) of the seed to the mJ level...
Solid-immersion lens (SIL) microscopy requires the dimensions of the SIL to be precisely fabricated, otherwise spherical aberrations will be encountered [1]. Uncorrected spatial aberrations not only degrade the lateral and axial resolutions of a sub-surface microscopy system, but also couple into the time domain to stretch the pulses beyond their minimum transform-limited durations [2]. Chromatic...
Among the crystals used in laser development, the cubic ones are often considered because of their simplicity and their optical isotropy, leading to several advantages for thermal management and growing properties. However, in high power lasers, it is important to consider the thermally-induced birefringence and anisotropy sources. In this work we report on measurements of the thermal lenses anisotropy...
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