WS7-60 Series

High Precision Wavelength Meter

Typical Applications

The WS7-60-series offers an accuracy of 60 MHz. It is a compact, versatile multipurpose wavelength meter for a laser laboratory.

The integrated calibration source makes it a compact solution for high-end laser applications with an absolute accuracy of 60 MHz and a wavelength deviation sensitivity of 2 MHz.

Available Measurement Ranges

WS7-60 Standard (VIS)

330 – 1180 nm

WS7-60 UV-I

248 – 1180 nm

WS7-60 UV-II

192 – 800 nm

WS7-60 IR-I

530 – 1750 nm

WS7-60 IR-II

1000 – 2250 nm

Absolute (and Other) Accuracies 1)

192 – 330 nm (with multi mode fiber)

0.2 pm

330 – 420 nm

0.04 pm

420 – 1100 nm

60 MHz

1000 – 2250 nm

40 MHz

Quick coupling accuracy (with multi mode fiber)

150 MHz

Wavelength deviation sensitivity/Measurement resolution 2)

2 MHz

Linewidth estimation accuracy 3)

200 MHz

Measurement Speed

500 Hz

Required Input Energy and Power 4)

Standard (VIS)

0.02 – 15 μJ or μW

UV-I

0.02 – 10 μJ or μW

UV-II

0.04 – 400 μJ or μW

IR-I

2 – 200 μJ or μW

IR-II 5)

2 – 80 μJ or μW

FSR of the Fizeau Interferometers (Fine/Wide Mode)

8 GHz/32 GHz (each instrument in each mode can measure lasers with a linewidth up to 30 % of the correspondig FSR)

Calibration

Built-in calibration

WS7-60 IR-I, IR-II, and UV-II require external calibration source, e.g. SLR-1532 or stabilized HeNe

Recommended calibration period ≤ 14 days

Warm-up Time

No warm-up time under constant ambient conditions; WS7-60 IR-II: 30 min. warm-up, or until ambient equilibrium

Dimensions L × W × H

360 × 200 × 120 mm

Weight

5.9 kg

Interface

High-speed USB 2.0 connection

Power Supply

Power consumption 2.3 W, power provided directly via USB cable WS7-60 IR-I and WS7-60 IR-II: external power supply included

1)According to 3σ criterion, but never better than 20 % of the laserlinewidth.

2)Standard deviation. WS7-60 requires singlemode fibers to reach thisresolution.

3)Not better than 20 % of thelinewidth.

4)The CW power interpretation in [μW] compares to an exposure of 1 s (generally the energy needs to be divided by the exposure time to obtain the requiredpower).

5)μJ interpretation for pulsed lasers. CW signals need more power in [μW] since the exposure is limited at IR-IIinstruments.

Options

External Trigger (TTL)

All wavelength meters detect and measure pulsed signals automatically. Additionally, this option allows the user to trigger pulsed measurements externally. The TTL option guarantees synchronization between pulsed excitation and measurement. It provides low-noise signals without parasitic parts when measuring pulsed signals with low duty cycles.

Laser Control (PID)

With the PID option it is possible to stabilize the frequency of a laser connected to the wavelength meter using a software based proportional-integral-derivative controller (PID controller). Unlike analog PID electronics, the PID option provides software based signal processing, allowing the laser to be stabilized to a specific user defined frequency or regulated with an arbitrary pattern. This makes it extremely useful in experiments where the laser frequency has to be actively regulated or varied to fit changing experimental conditions, such as laser cooling, atomic detection, trapping and spectroscopy. Combined with the MC option the wavelength meter can be used to stabilize multiple lasers simultaneously. The regulation speed, quality and absolute accuracy match the measurement speed, relative accuracy and absolute accuracy of the wavelength meter respectively. The measurement speed is not affected by the regulation.

Multichannel Switch (MC)

In order to measure the frequencies of more than just one laser at a time, an opto-mechanical switch is used. The combination of our high-speed wavelength meters with one of the quickest fiber switches (MEMS) available allows up to eight channels to be measured almost simultaneously. Exposure time and other parameters can be defined independently for each light source. You can choose between singlemode or multimode fiber switches, depending on the required accuracy level of your measurements.

Linewidth Estimation (L)

The linewidth estimation of a singlemode laser source is performed by a special algorithm which eliminates the interferometer’s instrument response function. The algorithm enables the estimation of the linewidth with an accuracy better than the tenth of the instrument FSR. 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 multiline spectrum. Any instrument can be upgraded with the L-option. Singlemode fibers are required.

External Calibration (CAL)

Standard HighFinesse wavelength meters up to an absolute accuracy of 60 MHz feature autocalibration via an integrated calibration ource. This guarantees the accuracy and stability of measurements with our wavelength meters. For the higher accuracies we offer a variety of frequency stabilized, narrow linewidth, laser sources with up to ± 10 kHz frequency stability for different applications.