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WS8 series

High-end Wavemeter for Unrivaled Precision

WS8 series

High-end Wavemeter for Unrivaled Precision

Unsurpassed Accuracy World-Wide

The HighFinesse/Ångstrom WS8 is the unsurpassed high-end instrument for wavelength measurement of pulsed or continuous laser sources. It delivers superb absolute and relative accuracy required by cutting-edge scientific research, as well as industrial and medical applications. The unmatched precision of the WS8 series and all of our other wavemeters is achieved by using non-moving, temperature controlled Fizeau interferometers in a unique geometric configuration.

Photonic Crystal Switch

The photonic fiber switch at the input offers endlessly singlemode operation and enhances the convienience by making it possible to measure distant laser wavelength at the same time.

Easy of Use & Customization

The WS8 is connected to the PC via a USB interface and is ready for use as soon as the software delivered with the device is installed. A compact, thermally insulated housing holds the optical elements as well as the electronics. The design enables the integration of additional options, allowing customized solutions to specific applications even years after purchase.

Technical Information

Measurement Range Ability



(330-1180 nm)
x x
(248-1180 nm)
(630-1750 nm)

Absolute Accuracy 2

192-330 nm 3 0.1 pm
330-420 nm 0.01 pm 0.01 pm
420-1100 nm 2 MHz 10 MHz
1100-2250 nm 10 MHz

Wavelength deviation sensitivity

200 kHz 3 400 kHz

Measurement Speed

up to
Standard, UV-I 500 Hz 500 Hz
IR-I 1200 Hz

1) UV (<350 nm) under development
2) According to 3σ criteria, please consult our technical brochure for details about the required calibraton wavelengths to realize the full accuracy of the devices
3) In certain ranges, 100 kHz available on request

Multi Channel (MC)

In order to measure the frequencies of more than just one laser at a time, an opto-mechanical switch is used. The switch contains a photonic crystal fiber output to guarantee endlessly singlemode operation. The combination of our highspeed wavelength meters with one of the quickest fiber switches available allows the measurement of up to 8 channels almost simultaneously. Exposure time and other parameters can be defined independently for each light source. For WS8 series the use of a switch is obligatory as the wavelength meter is specially adapted to the properties of the photonic crystal fiber.

Laser Control (PID)

As opposed to bulk error signal generation, the PID option provides full signal processing, accomplished by a software-based Proportional-Integral-Derivative (PID) controller. This option is very useful in experiments where the laser frequency has to fit changing experimental conditions, such as laser cooling, atomic detection, trapping and manipulation as well as Raman spectroscopy and other experiments where the laser frequency has to be actively regulated.

The regulation speed generally is the measurement speed of the Wavelength Meter. Regulations do not slow down the measurements. The regulation quality is the same as the Wavelength Meters‘ measurement deviation sensitivity and the absolute regulation accuracy is the same as the device‘ absolute measurement accuracy.

The PID option can do even more: It provides a function generator enabling the user to make the laser’s frequency follow any arbitrary mathematical function, e.g. a sine, triangle, rectangle, stairs, trapezoid functions, etc. or any combination thereof.

Linewidth Measurement (L)

The linewidth estimation of a single-mode laser source is performed by a special algorithm which eliminates the interferometer’s instrument response function. The algorithm enables the estimation of the linewidth several times better than the spectral resolution of the instrument.

The linewidth option can also be used for measuring the linewidth of multimode lasers or lasers with sidebands. In this case, the longitudinal mode splitting needs to be less than the instruments spectral resolution and the calculated result is the FWHM of the envelope function of the multi-line spectrum. Any instrument can be upgraded with the L-option, except IR3 devices. Single mode fibers are required.

External Trigger (TTL)

Usually all wavemeters detect and measure pulses automatically. This option allows the user to trigger pulsed measurements externally. There are two different ways to trigger. In mode 1 the TTL-pulse starts the read out of the arrays. Afterwards the CCD-arrays are illuminated until the next TTL-pulse is detected. In mode 2, the TTL-pulse starts the measure ment for a user-defined period of time.

The TTL option guarantees synchronization between pulsed excitation and measurement. It provides low-noise, pollution-free signals when measuring pulsed signals with low duty cycles

Applications, Notes and Downloads


High resolution spectroscopy can be replaced by a HighFinesse / Ångstrom Wavelength Meter. Absolute measurement and regulation accuracy in MHz-range is reached in the spectral range of 350 – 1750 nm. In UV (192 – 350 nm) 100 MHz regulation accuracy is possible. High measurement and feedback speed for in-situ frequency control of cw-laser-sources like singlemode diode lasers, DFB lasers, Dye lasers, TiSa laser or any pulsed laser application (LIDAR) is reached.


  • Technical Specifications WS8 Download


For further technical information, application examples, diagrams and for customization of the wavemeter please consult the Subsite or please contact: info@highfinesse.de


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