Philipp Huke

Philipp Huke
Hochschule Emden/Leer · Faculty of Technology

Professor

About

60
Publications
7,344
Reads
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416
Citations
Citations since 2017
32 Research Items
321 Citations
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20172018201920202021202220230102030405060
20172018201920202021202220230102030405060
20172018201920202021202220230102030405060
Additional affiliations
September 2020 - present
Hochschule Emden/Leer
Position
  • Professor
Description
  • Group Optical Metrology
December 2014 - August 2020
Georg-August-Universität Göttingen
Position
  • Researcher
November 2009 - October 2014
Bremer Institut für angewandte Strahltechnik GmbH
Position
  • Group Leader
Education
April 2005 - February 2009
Leibniz Universität Hannover
Field of study
  • Optical Metrology
September 2002 - November 2004
Leibniz Universität Hannover
Field of study
  • Applied Physics
September 1998 - August 2002
Hochschule Emden/Leer
Field of study
  • Applied Lasertechnology

Publications

Publications (60)
Article
Full-text available
Direct metal deposition (DMD) can be used for the cladding of surfaces as well as repairing and additive manufacturing of parts and features. Process monitoring and control methods ensure a consistent quality during manufacturing. Monitoring by optical emission spectroscopy of the process radiation can provide information on process conditions and...
Conference Paper
Light of a stabilized laser frequency comb is coupled into a multimode fiber and recorded with a Fourier-Transform spectrometer. The interferograms consist of equidistant, burst-like interference signals, which decorrelate due to modal dispersion and distribution.
Preprint
Full-text available
HIRES will be the high-resolution spectrograph of the European Extremely Large Telescope at optical and near-infrared wavelengths. It consists of three fibre-fed spectrographs providing a wavelength coverage of 0.4-1.8 mic (goal 0.35-1.8 mic) at a spectral resolution of ~100,000. The fibre-feeding allows HIRES to have several, interchangeable obser...
Article
Full-text available
p>Aims. We analyse the Signal-to-Noise Ratio (SNR) requirements of the European Space Agency (ESA)-funded Solar Coronagraph for OPErations (SCOPE) instrument with respect to the manual and automatic detection of Coronal Mass Ejections (CMEs) in its field of view of 2.5 to 30 solar radii. Methods. For our analysis, SNR values are estimated from obse...
Preprint
Full-text available
Statistical analyses from exoplanet surveys around low-mass stars indicate that super-Earth and Neptune-mass planets are more frequent than gas giants around such stars, in agreement with core accretion theory of planet formation. Using precise radial velocities derived from visual and near-infrared spectra, we report the discovery of a giant plane...
Article
We have used a laser frequency comb with a repetition frequency of νrep≈1 GHz to measure the drift and dispersion of a Fourier-transform spectrometer (FTS). We used the electronic measurements of νrep and νCEO to create a reference line list. We measured 28 interferograms and computed the phase and power spectra. The analysis of the interferograms...
Preprint
Full-text available
Context. Teegarden's Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0V), the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES. Aims. As part of the CARMENES search for exoplanets around M dwarfs, we obtain...
Article
Full-text available
Fourier-transform spectrographs (FTS) are among the most important tools for high-resolution spectroscopy over a broad spectral bandwidth. Usually, the frequency axis of an FTS is calibrated with relatively few atomic lines and an absolute wavelength reference, which is often a stabilized He–Ne laser. Normally, the phase-spectrum is measured using...
Poster
Full-text available
At the Institute for Astrophysics G¨ottingen we have a very special combination of instruments: A 50 cm Siderostat with a vacuum vertical telescope, a very high resolution Fourier Transform Spectrograph (R > 900; 000 at 600 nm in double sided mode) and a Laser Frequency Comb for extremely precise and accurate frequency calibration. The spectrograph...
Article
Absorption cells filled with diatomic iodine are frequently employed as wavelength reference for high-precision stellar radial velocity determination due to their long-term stability and low cost. Despite their wide-spread usage in the community, there is little documentation on how to determine the ideal operating temperature of an individual cell...
Conference Paper
We present precise broadband measurements of absorption and dispersion spectra of carbon monoxide 0-3 band in argon. They were performed using frequency comb cavity mode width and dispersion spectroscopies with a mechanical FTS setup.
Article
Context . Thorium hollow cathode lamps (HCLs) are used as frequency calibrators for many high resolution astronomical spectrographs, some of which aim for Doppler precision at the 1 m s ⁻¹ level. Aims . We aim to determine the most suitable combination of elements (Th or U, Ar or Ne) for wavelength calibration of astronomical spectrographs, to char...
Preprint
Absorption cells filled with diatomic iodine are frequently employed as wavelength reference for high-precision stellar radial velocity determination due their long-term stability and low cost. Despite their wide-spread usage in the community, there is little documentation on how to determine the ideal operating temperature of an individual cell. W...
Article
Full-text available
We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V = 8.9 mag, M = 0.58 ± 0.08 M), a bright M0.0 V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of K = 5.1±0.4 m s −1 an...
Article
Full-text available
The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520--1710nm at a resolution of at least $R > 80,000$, and we measure its RV, H$\alpha$ emission, and project...
Article
Full-text available
Context. The main goal of the CARMENES survey is to find Earth-mass planets around nearby M-dwarf stars. Seven M-dwarfs included in the CARMENES sample had been observed before with HIRES and HARPS and either were reported to have one short period planetary companion (GJ 15 A, GJ 176, GJ 436, GJ 536 and GJ 1148) or are multiple planetary systems (G...
Article
Full-text available
The first generation of E-ELT instruments will include an optical-infrared High Resolution Spectrograph, conventionally indicated as EELT-HIRES, which will be capable of providing unique breakthroughs in the fields of exoplanets, star and planet formation, physics and evolution of stars and galaxies, cosmology and fundamental physics. A 2-year long...
Article
On March 20, 2015, we obtained 159 spectra of the Sun as a star with the solar telescope and the FTS at the Institut f\"ur Astrophysik G\"ottingen, 76 spectra were taken during partial solar eclipse. We obtained RVs using $I_2$ as wavelength reference and determined the RM curve with a peak-to-peak amplitude of almost 1.4 km s$^{-1}$ at typical RV...
Conference Paper
The first generation of E-ELT instruments will include an optical-infrared High Resolution Spectrograph, conventionally indicated as EELT-HIRES, which will be capable of providing unique breakthroughs in the fields of exoplanets, star and planet formation, physics and evolution of stars and galaxies, cosmology and fundamental physics. A 2-year long...
Conference Paper
Hollow cathode discharge lamps (HCLs) have been successfully used in recent years as calibration sources of optical astronomical spectrographs. The numerous narrow metal lines have stable wavelengths, which makes them well suited for m/s calibration accuracy of high-resolution spectrographs, while the buffer-gas lines are less stable and less usefu...
Article
We report on the experimental realization of locking a Fabry-Perot interferometer (FPI) onto a stabilized diode laser for the calibration of astronomical spectrographs. The external cavity diode laser (ECDL) is stabilized to the 85Rb+ F∗ = 2 → F = 3 transition with a pump-probe setup. The stability of the 85Rb+ reached between optical clocks is on...
Article
Full-text available
We report about the efficient generation of Lamb waves for nondestructive testing (NDT) of carbon fiber reinforced plastics (CFRP) with spatially formed laser beams. Therefore we describe the successful introduction of a liquid crystal on silicon (LCoS)-based spatial light modulator (SLM) to create predetermined spatial laser light distributions fo...
Conference Paper
Phase-measuring deflectometry is a powerful method to measure reflective surfaces. It is relatively easy to extract slope and curvature information from the measured phase maps; however, retrieving shape information depends very sensitively on the calibration of the camera and the geometry of the measurement system. Whereas we have previously demon...
Conference Paper
Nondestructive testing of objects is the basis for quality control in a production line. There exists a wide range of optical and tactile methods for the detection of surface defects. For hidden defects (below the surface) different methods like Xray or ultrasound are state of the art; also, optical methods like thermography and interferometry can...
Article
The application of laser ultrasound for nondestructive testing of carbon fiber-reinforced plastics (CFRP) and carbon fiber-reinforced thermoplastics (CFRTP) is shown. Laser-generated excitation creates a three-dimensional, thermoelastic zone which emits ultrasound waves during expansion and contraction. In order not to exceed the damage threshold o...
Article
Full-text available
The verification of kissing bond defects with conventional nondestructive testing techniques is generally unsuccessful because kissing bonds behave very similar to an intact adhesive. Therefore, one has to apply a suitable method such as loading the adhesive joint using laser-generated shock waves in order to make this kind of defect detectable. Th...
Article
Full-text available
We report on a 3.3 μm laser/optical parametric oscillator system with 4.7 mJ pulse energy for laser ultrasound measurements of carbon-fiber-reinforced materials. The OPO was pumped by a compact diode-pumped Nd:YAG master-oscillator power-amplifier system with two amplifier stages. First results of laser ultrasound measurements are presented.
Article
Non-destructive testing (NDT) describes a wide range of methods for measuring and comparing physical quantities against a nominal condition. In this paper we describe and compare different optical NdT (ONDT)-methods with respect to their characteristics and capability for different measurement tasks. ONDT may be specified in two categories, passive...
Article
Full-text available
We present a method to record the wear on samples of micro deep drawing tools. The method is based on the basic idea of comparative holography and captures three dimensionally the surface of the tool in the initial state and compares it with used state after processing several parts. The comparison reveals scratches and other effects caused by wear...
Article
IntroductionPrinciples of Optical Nondestructive Testing Techniques (ONDTs)Optical Methods for NDTConclusions and PerspectivesAcknowledgmentsReferences
Conference Paper
Also available on NDT.net, vol. 17, january 2012 http://www.ndt.net/article/ndtp2011/papers/31_Sfarra_Rev1.pdf
Article
Standard ultrasound methods using a phased-array or a single transducer are commonly used for non-destructive evaluation (NDE) during manufacturing of carbon fiber reinforced plastics (CFRP) parts and certificated testing schemes were developed for individual parts and geometries. However, most testing methods need direct contact, matching gels and...
Article
High precision optical metrology may be viewed from the perspective of the relevant object properties for optical measurement such as microstructure, surface gradient and geometrical complexity. We discuss high precision measurement methods and compare their suitability with respect to these object properties. We emphasize reflectometry and shearog...
Article
We present a novel approach to investigate the shape of a diffusely reflecting technical object. It is based on a combination of a multiple‐illumination contouring procedure and phase retrieval from a set of intensity measurements. Special consideration is given to the design of the experimental configuration for phase retrieval and the iterative a...
Article
Full-text available
Optical methods are extremely useful for Non Destructive Testing (NDT) due to their ability to measure fast and contactless, to test larger areas or tiny spots in a short time, and to measure on complex shaped parts as well as plane surfaces. In this paper we present laboratory setups for NDT available at BIAS and corresponding results. We present...
Article
We present a novel approach to investigate the shape of a diffusely reflecting technical object. It is based on a combination of a multiple-illumination contouring procedure and phase retrieval from a set of intensity measurements. Special consideration is given to the design of the experimental configuration for phase retrieval and the iterative a...
Article
Full-text available
The development of a modified stripe-pattern projection system that uses linescan cameras is presented. The system measures complex-shaped sheet metal parts (>3 m2) and enables the detection of dents (>30 mum) and other defects. Therefore, the measurement system is moved and the parts are scanned line by line. The parallel investigation of a simula...
Article
Full-text available
We present a simple scheme for tuneable relative frequency stabilization of lasers. A highly sensitive and accurate frequency-to-voltage converter is used to derive an error signal from the beat note between two lasers. We analyze in detail detector noise and drift, modulation detection bandwidth, and cross-talk from power modulation. The results i...
Article
We present a diode laser concept for precision spectroscopy which is based on a novel optical feedback scheme that combines excellent frequency stability (<35kHz linewidth in 290ms) with good tuneability (45 GHz continuously, 50nm overall).
Article
Full-text available
We present theoretical and experimental investigations on a new optical feedback concept for single mode diode lasers. It is based on the optical feedback from a resonant external cavity coupled to the diode laser through the 1st order diffraction of a grating. With a single mode diode laser operating at 852 nm we demonstrate a short term line widt...
Conference Paper
We report on the development of a diode laser system which is optimized for precision spectroscopy. It is based on a combination of diode lasers with optical feedback from a grating and diode lasers with optical feedback from a resonant cavity. So far we have achieved overall tuneabilities on the order of 50 nm, continuous tuneabilities in excess o...
Conference Paper
We demonstrate a linewidth of 35 kHz with a single mode diode laser operating at 852 nm phase-locked to another laser system that is frequency locked to a Cs-transition. A large continous tuning range in excess of 45 GHz and single mode operation were shown from 829.2 nm to 874.1 nm at constant diode temperature. The external cavity is stabilized t...
Article
We describe a concept for diode lasers with optical feedback. It is based on the combination of two different diode laser concepts: the diode laser with (i) feedback from a grating and (ii) resonant optical feedback from a separate cavity. The goal of our work is to unite the excellent tunability and well known reliability of grating diode lasers w...

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Projects

Projects (2)
Project
The foreseen E-ELT instrumentation plan includes a high -resolution spectrograph (HIRES). One of its aims is to detect and quantify exoplanets atmospheres. Therefore, the fiber-fed spectrograph aims at very high RV-precision. For one of its since cases it even needs 2 cm/s. In addition a high SNR is needed, which in turn requires a sophisticated calibration strategy.
Project
The Project aims at the realization of a method for an automated quality inspection of cold formed micro parts. The result will be a fast and calibrated 3D-metrology system that can automatically measure deviations of object geometries in a measurement volume of about 1 mm3.