arXiv subjects

Ondrej Kitzler

Publications and source records attributed to Ondrej Kitzler.

5 recordsLinked to original sources

arXiv2026

The Calibration System of the iLocater Spectrograph

iLocater is a new near-infrared, extreme precision radial velocity (EPRV) instrument delivered to the Large Binocular Telescope in the summer of 2026. The instrument utilizes single-mode fibers (SMFs) for light transmission, including its calibration systems. We present an overview of the iLocater calibration system, detailing the specific sources and the hardware required to inject calibration light into the SMFs. Furthermore, we discuss the hardware that efficiently switches between these sources and distributes the light to all necessary instrument locations, entirely eliminating the need for free-space propagation.

astro-ph.IM↗

arXiv2026

Commissioning and on-sky performance verification of iLocater

iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over $λ=966-1312$ nm with a median resolving power of $R=205,000$ as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close ($θ< 1''$) binary stars.

astro-ph.IM↗

arXiv2026

Laboratory characterization of iLocater

iLocater is a diffraction-limited, fiber-fed spectrograph designed for the Large Binocular Telescope (LBT), which targets high-precision radial velocity measurements in the near-infrared. Prior to deployment, comprehensive laboratory characterization was essential to validate instrument performance and inform alignment strategies. This paper presents results from four key areas of lab characterization: (1) adjustment and optimization of detector orientation to optimize spectrum alignment with the detector pixel grid across the focal plane; (2) the design and installation of a LED illumination source to enable high-fidelity flat-fields; (3) a model-based focusing methodology using OpticStudio image simulations to optimize the optical alignment of the spectrograph; and (4) assessment of instrument mechanical and optical stability under laboratory conditions. Together, these efforts established baseline performance metrics and demonstrated instrument readiness for delivery and on-sky commissioning.

astro-ph.IM↗

arXiv2020

Coherent Raman pulses with quantum-randomized polarization

We demonstrate the generation of coherent Stokes pulses with randomized linear-polarization in diamond, when the pump wave-vector and linear polarization were oriented along the $[110]$ and $[1\bar{1}0]$ axes respectively. In this configuration the excitation of multiple Raman modes produces isotropic gain, preventing the Stokes pulse from acquiring a deterministic orientation and is instead randomized by the zero-point motion of the crystal. Experimental polarization measurements were consistent with an independent, identical distribution with an estimated entropy rate of 6.67 bits per pulse.

quant-ph↗

arXiv2018

Diamond Brillouin Lasers

The coherent interaction between optical and acoustic waves via stimulated Brillouin scattering (SBS) is a fundamental tool for manipulating light at GHz frequencies. Its narrowband and noise-suppressing characteristics have recently enabled microwave-photonic functionality in integrated devices based on chalcogenide glasses, silica and silicon. Diamond possesses much higher acoustic and bandgap frequencies and superior thermal properties, promising increased frequency, bandwidth and power; however, fabrication of low-loss optical and acoustic guidance structures with the resonances matched to the Brillouin shift is currently challenging. Here we use intense cavity-enhanced Raman generation to drive a diamond Brillouin laser without acoustic guidance. Our versatile configuration - the first demonstration of a free-space Brillouin laser - provides tens-of-watts of continuous Brillouin laser output on a 71 GHz Stokes shift with user switching between single Stokes and Brillouin frequency comb output. These results open the door to high-power, high-coherence lasers and Brillouin frequency combs, and are a major step towards on-chip diamond SBS devices.

physics.optics↗