iScan®
Instrument zur schnellen und präzisen Steuerung von durchstimmbaren Laserquellen
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iScan-Ansteuerelektronik |
Beschreibung:
Das iScan-System ist ein universelles Hilfsmittel zur Überwachung, Analyse und Regelung von durchstimmbaren Laserquellen.
Es wurde speziell als Werkzeug für den Einsatz in Forschungslabors zum statischen und dynamischen Testen der Modeneigenschaften von durchstimmbaren Lasern entworfen, erlaubt aber deutlich mehr:
 | Schnelles, präzises und hysterefreies Scannen durchstimmbarer Laser |
| Anfahren verschiedener wohldefinierter Wellenlängen |
| Beobachtung des Scanverhaltens durchstimmbarer Laser |
| Messung der Wellenlängenstabilität durchstimmbarer Laser |
| Vermeidung von Modensprüngen oder Modeninstabilitäten |
Datenblatt:
Download application note
(Precision Frequency Metrology and Stabilization For Continuous Wave (cw) THz
Sources Based on Two-Color Laser Mixing)
Preise:
auf Anfrage
Anwendungsbeispiele:
1. Erzeugung von frequenzstabiler, durchstimmbarer Dauerstrich-Terahertz-Strahlung
A. Deninger, Th. Kinder, Th. Müller-Wirts and F. Lison:
High-Power Dual-Color Diode Laser System with Precise Frequency Control for
CW-THz Generation.
Optical Society of America, 2007
A. Deninger, Th. Göbel, D. Schönherr, Th. Kinder, A. Roggenbuck, M. Köberle, F.
Lison, Th. Müller-Wirts and P. Meissner:
Precisely tunable continuous-wave terahertz source with interferometric
frequency control.
REVIEW OF SCIENTIFIC INSTRUMENTS 79, 044702 (2008)
"A continuous-wave terahertz (CW-THz) spectrometer was constructed using a
photomixing radiation source, Fig. 1. The instrument can be divided into the
following functional units: a dual-frequency optical source, the photomixer
element, a THz beam propagation path including the sample cell and a detector (bolometer).
The optical source contains two (Toptica DL-100) extended cavity diode lasers (ECDL)
operating at 780nm. The lasers are spatially mixed using a beamsplitter to
create a beat note in the THz frequency range. In order to optimize the spectral
resolution of the source, a frequency stabilization scheme was applied to each
laser. The first laser was frequency locked to a saturated absorption feature of
the rubidium D2-line, using commercially available apparatus
(TEM Messtechnik, CoSy). The second laser was stabilized using a
low-contrast Fabry–Perot interferometer system (TEM Messtechnik, iScan). Unlike
many Fabry–Perot systems that can only provide information at the resonant
frequency, the advantage of this low-contrast interferometer is that it is
capable of providing a stabilization signal at any frequency. An error signal
generated by the difference between an arbitrary set-point and the Fabry–Perot
is applied to the piezo electric element of the laser. Hence the laser can be
frequency scanned across its gain profile with an active frequency correction
being provided by the interferometer. In the particular case of an ECDL, the
fine adjustment of the grating alignment using the piezoelectric allows a
continuous tuning range of around 10GHz to be routinely obtained. Larger
frequency steps are realized by manual adjustments of the grating alignment
along with current
and temperature of the laser diode."
Zitat aus:
2. Rydberg-Spectroscopie an Rubidium
"The One Atom Maser, or Micromaser is a cavity Q.E.D. experiment consisting of a high-Q superconducting microwave cavity which interacts with a sequence of single 2-level Rydberg atoms. [...] In particular I develop a 3-step laser excitation system for Rubidium Rydberg states, which I present together with the most accurate Rydberg spectroscopy to date of Rubidium P states with principal quantum number 36 to 63, from which quantum defects and an accurate value of the ionisation energy of Rubidium is derived. Work on locking multiple lasers to a single frequency comb, thus performing accurate multi-step spectroscopy is presented."
Five different diode lasers are used in the micromaser experiment: [...] The velocity-selecting 780 nm laser is locked to a specific offet frequency relative to the first laser, employing a commercial cavity (iScan).
This system, together with a temperature controller, a PID and a laser controller is commercially available in the form of the iScan from TEM Messtechnik. We used this apparatus to lock a laser, reliably and linearly scan it over tens of GHz and have it rapidly jump from one frequency to another within 8 GHz. When optimally set up, the frequency resolution is on the order of 300 kHz, mainly limited by the resolution of the photodiodes and electronics. The Allan deviation of this system was measured by beating a Toptica DL 100 laser locked to the iScan with a line of a frequency comb (see Section 3.3) and recording the resulting beat-note. The Allan deviation was observed to stay below 2 MHz for approximately 30 minutes, and the thermal drift rate was measured to be approximately 2 MHz/hour."
Zitat aus:
