CoSy head and control module for Doppler-free saturation spectroscopy

CoSy

Compact Unit for Doppler-free Absorption Saturation Spectroscopy

The CoSy system is a versatile tool for Doppler-free absorption saturation spectroscopy. This permits a generation of extremely precise defined wavelength standards, which can be used for highly precise stabilization of tunable lasers.

  • The CoSy head contains the setup for the Doppler-free saturation spectroscopy. It is available with Cesium-, Rubidium- or Potassium cells (other cells on request)
  • The CoSy head is controlled by the power supply and control electronics CoSyControl

Usually Doppler-free absorption saturation spectroscopy is achieved by using a relatively complex opto-mechanical setup. This setup has been integrated in the described small compact unit, together with the electronics needed for evaluation of the detected beams.

At the outputs a ‘Doppler-free absorption saturation spectrum’ is directly available and can be visualized on e.g. an oscilloscope. Thus, the used laser can be stabilized towards the detected atomic lines. This can be achieved for example with the stabilization electronics LaseLock →.

One easily achieves a long-term stability of the optical frequency below 1 MHz (corresponding to a relative stability of 10-9)

CoSy head and control module for Doppler-free saturation spectroscopy

CoSy-I2

Compact Unit for Doppler-free Absorption Saturation Spectroscopy using iodine vapor

TEM Messtechnik presents its compact spectroscopy unit CoSy with a new species of absorptive gas: vapor of molecular iodine.

For the use of cw single-frequency lasers for high precision metrology applications, in many cases an accurate determination (and sometimes even stabilization) of their oscillation frequency is prerequisite. Luckily nature provides us with ubiquitous standards to which optical frequencies can be referred: Electronic transitions in atoms and molecules often coincide with the emission or absorption of light in a narrow frequency interval (“spectral lines”). Thus, to determine an optical frequency means simply to detect emission or absorption of the light by matter (“spectroscopy”). The iodine-stabilized helium-neon laser is one of the text book examples for this method.

For visible light, a vapor of iodine molecules is a good candidate for such a frequency standard because it provides a dense line spectrum up to 583 THz (down to 514 nm) with a natural linewidth as low as ~380 kHz. Its optical properties have therefore been investigated in detail. The BIPM even recommends to use certain absorption lines for the realization of the meter (as a certain multiple of the wavelength of a laser stabilized to the iodine absorption frequency), for example the a10 component of the transition R(56)32-0 near 563 260 224 MHz.

CoSy-I2 Absorption Spectrum
Typical absorption spectrum of the I2 molecule red: Doppler-broadened, blue: Doppler-free hyperfine structure revealed by TEM Messtechnik’s compact spectroscopy unit CoSy.

Pricing (EU-Countries)

ItemDescriptionUnit Price (EUR)
CoSy Fc Rb-Cs-KCompact saturation spectroscopy unit, cell filled with rubidium, cesium and potassium, including fiber coupler and coil for magnetic field compensation3700,00€
CoSy-I2-532Compact saturation spectroscopy unit, cell filled with iodine, including fiber coupler, for 532nm4392,00€
CoSy-I2-633Compact saturation spectroscopy unit, cell filled with iodine, including fiber coupler, for 633nmon request

8 % surcharge for non-European countries plus shipment and possible import duties/taxes in the destination country.