Application Reports
Stabilization of an optical cavity with a three-mirror image inverter
A. Kosuge, M. Mori, H. Okada, R. Hajima, K. Nagashima: Stabilization of an optical cavity with a three-mirror image inverter for generation of laser Compton scattered ?-rays. Advanced Solid-State Lasers Congress Technical Digest, OSA 2013 →
“By using a three-mirror image inverter which inverts a phase of the specific polarizing direction, we can obtain an “error signal” to lock a cavity without any transmission element […]. … It can be used successfully to lock the cavity to resonance by means of a digital-based cavity lock system (TEM Messtechnik GmbH).”
Seeding of an OPO for generation of terahertz radiation
D. Molter, M. Theuer, and R. Beigang:
Nanosecond terahertz optical parametric oscillator with a novel quasi phase matching scheme in lithium niobate. →
Optics Express, Vol. 17, Issue 8, pp. 6623-6628 (2009) doi:10.1364/OE.17.006623
“We present an optical parametric oscillator pumped by a single mode Q-switched nanosecond Nd:YVO4 laser for terahertz generation in periodically poled lithium niobate with a new phase matching scheme. This new method leads to an emission of terahertz radiation close to the Cherenkov angle and to a parallel propagation of the pump and signal wave. The emission frequency of this novel source is chosen by the poling period to 1.5 THz. For spectral narrowing the signal wave of the OPO is injection seeded. In the optical spectrum also cascaded processes are observed demonstrating a powerful generation of terahertz waves. The OPO itself is also seeded by a grating stabilized diode laser tunable from 1064 nm to at least 1076 nm. Therefore this seed laser is in principle useful to build OPOs for THz frequencies up to 3 THz when pumped at 1064 nm. For the purpose of cavity length stabilization we apply the Haensch-Couillaud stabilization scheme and a commercially available locking system.”
Tuneable heterodyne infrared spectrometer
G. Sonnabend, M. Sornig, P. Krötz, D. Stupar, R. Schieder:
Ultra high spectral resolution observations of planetary atmospheres using the Cologne tuneable heterodyne infrared spectrometer. →
Journal of Quantitative Spectroscopy & Radiative Transfer 109 (2008) 1016–1029
“High-resolution spectroscopy is a versatile tool to study planetary atmospheres. […] The paper will present a detailed description of the Cologne-based receiver THIS, the only tuneable heterodyne infrared spectrometer for application to astronomy offering access to the 7–17 mm wavelength region at a resolution of up to 3 107 and a bandwidth of 3 GHz.
To optimize the superposition of the signal and the laser and to provide a relative frequency standard a confocal FP ring resonator is used, the so-called diplexer. The diplexer consists of two focusing mirrors (focal length 30 mm) and two highly reflective beam splitters […] The locking process is performed in two steps: first, a stabilized Helium–Neon (HeNe) laser operating at 632 nm […] is fed into the diplexer […] . An error signal is provided by a lock-in amplifier which can then be used to actively control the diplexer resonances via the piezo actuator.
In a second step the transmission of the QCL through the diplexer is monitored via the DC component of the heterodyne detector. A second lock-in/feedback circuit is then used to keep the QCL emission at the maximum of the diplexer transmission curve. Following this procedure the LO can be stabilized in frequency to 1MHz RMS (see Section 2.3). […] The stabilization feedback loop consists of two LaseLock units manufactured by TEM Messtechnik.”
Precision spectroscopy
B Sanguinetti , H O Majeed , M L Jones and B T H Varcoe:
Precision measurements of quantum defects in the nP3/2 Rydberg states of 85Rb. →
J. Phys. B: At. Mol. Opt. Phys. Vol. 42 Nr. 16 pp.165004, 2009 L A M
Johnson, H O Majeed, B Sanguinetti, Th Becker and B T H Varcoe:
Absolute frequency measurements of 85Rb nP7/2 Rydberg states using purely optical detection. →
Tuneable cw-OPO
P. Haag:
Realization and electronical stabilization of diode laser pumped single-frequency continuous-wave optical parametric oscillators based on periodically poled lithium niobate.Doctoral thesis, Technische Universität Kaiserslautern, 2009
Injection-locking of a Ti:Sapphire laser for resonance ionization
Dep. of Quantum Engineering, Nagoya University, Japan and RIKEN Nishina Center, Japan, 2012:
Resonance Ionization Spectroscopy in gas jet using a high repetition rate Ti:Sapphire laser system at SLOWRI PALIS. →
University of Jyväskylä, Finnland, 2013:
Injection-locking of a Ti:Sapphire laser for resonance ionization →
Stabilisierung der Idler-Frequenz eines OPO auf einen Lamb-Dip in Methan →
B. L. Yoder, Steric Effects in the Chemisorption of Vibrationally Excited Methane on Nickel, Springer Theses, DOI: 10.1007/978-3-642-27679-8, Springer-Verlag Berlin Heidelberg 2012
Tobias Lamour, Stanford University (now MPQ Garching) says:
Tobias Lamour, Stanford University says: Taking over the task of locking several cavities with the TEM LaseLock was a difficult but rewarding task. We were able to stabilize systems reliably with unprecedented stability →
Generation of frequency-stabilized cw Terahertz radiation
Francis Hindle, Chun Yang, Arnaud Cuisset, Robin Bocquet, Gael Mouret:
A compact CW-THz spectrometer for applications to gas phase identification and quantification of multiple species →
Rydberg spectroscopy of Rubidium
Precision Laser Spectroscopy of Rubidium with a Frequency Comb. Luke Johnson, PhD thesis, University of Leeds, 2011. Pages 94, 95.
“To study the three-step stabilisation scheme, all three laser steps were stabilised to individual Rb reference cells. The first step laser was stabilised using the polarisation spectroscopy scheme introduced in Section 4.2; this is modulation-free. Active feedback for this laser lock was supplied via the laser cavity piezo and the diode injection current. The second step laser was stabilised using the separate co-propagating setup described in Section 4.3.9; FM was added to the laser via the diode injection current. Feedback for this lock was also supplied via the laser cavity piezo and the diode injection current. The third step was stabilised to a Rydberg signal such as those shown in Figure 5.1 and 5.2. Active feedback for this lock was supplied via the laser cavity piezo only. For all three stabilisation schemes, the error signals were sent through PID controllers and then to the laser drivers for feedback, via universal Laselock units (see Figure 5.4).
[…] With this setup it was possible to stabilise to the Rydberg states […]. In principle all states between these will also be accessible. However, for higher n, the lower SNR of the signals prevented a reliable third step lock. The only limiting factor was the available third step laser power.
The results from this study suggest that the absolute frequencies of Rydberg levels could be measured to an accuracy of <100 kHz using this locking technique. This far surpasses the accuracy of the work in Chapter 4, and would give an accuracy comparable to relative microwave spectroscopy measurements.”
