Economical Wavemeter (MWM)

In addition to the Fizeau wavemeter, there is also the compact and inexpensive MWM wavemeter from MOGlabs, which can be used to set a tunable laser to an exact wavelength. The wavelength can be selected between 370 – 1120 nm and the wavelength range is then ± 10 nm with an accuracy of 100 MHz. The MWM significantly resolves multimode laser operation (1) and is therefore particularly suitable for use with ECDLs, which are used as cooling or trapping lasers.
The following diagram shows the spectrum of a diode laser with an external resonator operating in several longitudinal modes of the semiconductor diode resonator. You can see a clear separation of the two diode modes.

Features

• Resolution of the wavelength readout 100 MHz (0.1 pm)
• Wavelengths available from 350 nm to 1100 nm (2)
• Picowatt input sensitivity (3)
• Identifies multimode input immediately
• Fast readout (4)
• CW or pulsed laser input
• Laser wavelength stabilization with PID feedback (5)
• Ethernet and USB included as standard
• Compact, 165 x 85 x 70 mm
• Independent, built-in display, can be driven by battery

(1) For accuraycy, please read MOGlabs‘ FAQ. Resolution and ability to resolve diode multimode oscillation depend on wavelength and diode. (2) Der Wellenlängenbereich beträgt 22 nm bei 780 nm. The devices are calibrated on delivery to a user-defined wavelength (e.g. 775 nm to 797 nm) and can then be set to other wavelengths in the range from 350 nm to 1100 nm with a user calibration. (3) FC/PC single-mode fiber input; FC/APC to FC/PC fiber is included. The sensitivity of the wavemeter is designed so that no fiber input lens or kinematic fixtures are required – simply hold the fiber end in the laser beam. (4) Measuring rate up to 1250 per second (on the device), up to 250 per second when using the mogwave Windows computer app. (5) 12-bit DAC output, 0.5 mV resolution.

Applications

• Laser frequency diagnosis and testing
• Identification of the multimode behavior of lasers
• Determination of absorption lines
• Gas spectrometry
• Raman fluorescence