Publications by authors named "Simon Herr"
Article Synopsis
- Tunable light sources are crucial for various applications like ranging, spectroscopy, and imaging.
- Whispering gallery resonator lasers, specifically neodymium-doped lithium niobate, offer low thresholds and improved tuning capabilities due to their linear electro-optic effect.
- The system achieves a tuning range of 3.5 GHz with good frequency and power stability, making it compatible with existing lithium niobate photonic platforms.
Nonlinear interferometers allow for mid-infrared spectroscopy with near-infrared detection using correlated photons. Previous implementations have demonstrated a spectral resolution limited by spectrally selective detection. In our work, we demonstrate mid-infrared transmission spectroscopy in a nonlinear interferometer using single-pixel near-infrared detection and Fourier-transform analysis.
View Article and Find Full Text PDFWhispering-gallery-mode resonators made of laser-active materials can serve as efficient microphotonic coherent light sources. However, the majority of experimental realizations relies on expensive pump light sources like narrow-linewidth or pulsed laser systems, which is inappropriate for most applications. In order to overcome this, we present a whispering-gallery laser system without the need for an expensive pump light source and at the same time with unprecedented laser performance: A laser-active resonator made of Nd:YVO is non-resonantly excited, employing a low-cost laser diode without any external frequency stabilization, emitting up to 100 mW optical power around 810 nm wavelength.
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- Optical frequency combs are essential for precise optical measurements, primarily operating in the near-infrared (NIR) range.
- Many applications require these combs to function at mid-infrared (MIR), visible (VIS), or ultraviolet (UV) wavelengths, which can be done through nonlinear optical processes, but it's tough for high-repetition-rate combs.
- Researchers show that a specific microresonator can efficiently convert high-repetition-rate NIR combs into VIS, UV, and MIR wavelengths, opening up new possibilities in fields like molecular sensing, astronomy, and quantum optics.
Article Synopsis
- Lasing and self-pumped optical parametric oscillation are achieved in a micro-resonator made of neodymium-doped lithium niobate, with a laser output of 5 mW.
- At 6 mW output power, the combined signal and idler outputs exceed 1.2 mW, generating light wavelengths from 1.5 to 3.8 μm.
- This is the first demonstration of a quasi-phase-matched self-pumped nonlinear optical process in a micro-resonator, indicating potential for a cost-effective, wavelength-tunable coherent light source.
Article Synopsis
- A millimeter-sized whispering-gallery resonator made from neodymium-doped lithium niobate can both lase and perform self-frequency doubling.
- A simple and inexpensive 808-nm laser diode is used to pump the neodymium ions, leading to laser output around 1.08 μm and producing green light through frequency doubling.
- This innovative technique is a first for combining lasing and frequency conversion in one high-Q resonator and could be applied to various materials and nonlinear optical processes.
Article Synopsis
- Ferroelectric domain walls are boundaries in materials where spontaneous polarization changes direction, leading to distinct properties.
- Recent research has achieved a significant breakthrough in lithium niobate, showing conductivity at charged domain walls that is over 13 times greater than the bulk material, with improved stability and accessibility.
- These advancements open up exciting possibilities for developing new optical components and advanced integrated devices for applications in quantum photonics.
Despite the need for isotropic optical resolution in a growing number of applications, the majority of super-resolution fluorescence microscopy setups still do not attain an axial resolution comparable to that in the lateral dimensions. Three-dimensional (3D) nanoscopy implementations that employ only a single objective lens typically feature a trade-off between axial and lateral resolution. 4Pi arrangements, in which the sample is illuminated coherently through two opposing lenses, have proven their potential for rendering the resolution isotropic.
View Article and Find Full Text PDFA new approach to the deposition of Mn12 single-molecule magnet monolayers on the functionalized Au(111) surface optimized for the investigation by means of scanning tunneling spectroscopy was developed. To demonstrate this method, the new Mn12 complex [Mn12O12(O2CC6H4F)16(EtOH)4].4.
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