Thorlabs' Optical Spectrum Analyzers (OSAs) perform highly accurate spectral measurements. Compatible with fiber-coupled and free-space light sources, these compact benchtop instruments suit a wide variety of applications, such as analyzing the spectrum of a telecom signal, resolving the Fabry-Perot modes of a gain chip, and identifying gas absorption lines.
Our Optical Spectrum Analyzers acquire the spectrum via Fourier transform, using a scanning Michelson interferometer in a push/pull configuration. This approach enables a high-precision Wavelength Meter mode with seven significant figures and ±1 part-per-million accuracy, allows robust statistical analysis of the acquired spectra, and provides broadband spectral measurements with every scan. Details are provided in the Design tab.
Thorlabs' Camera-Based Beam Profilers allow complex mode patterns (like flat top and donut) to be identified while optimizing a laser system. Compared to scanning slit beam profilers, camera beam profilers can capture a more detailed beam profile and provide a true 2D analysis of the beam's power density distribution.
These beam profilers are suited for use with either continuous wave or pulsed sources. Several trigger modes allow flexible capturing of single pulses, including a TTL input for triggered single pulse detection of signals with a repetition rate lower than 50 kHz. In non-trigger mode, pulses with repetition rates above 50 kHz will be seen as a continuous wave source by the beam profiler.
Thorlabs' Dual Scanning Slit Beam Profilers are ideal for analyzing cross sectional profiles of near-Gaussian laser beams. Measurements of the intensity profiles along the user-specified X and Y axes of the beam's cross section are acquired at scan rates between 2 Hz and 20 Hz, which can be set using the software. The fast 20 Hz scan rate enables real-time optical system alignment. Primarily intended for CW laser beams, >10 Hz pulsed beams can also be measured using an averaging technique (see the Operation tab for more information). These measurements can be used for beam quality evaluation, examination of the reconstructed beam profile, and monitoring long-term stability.
These extension sets are designed to convert Thorlabs' Camera or Scanning Slit Beam Profilers into a fully automated, motorized M² measurement system. The M2MS has internal mirrors for wavelengths between 400 - 2700 nm and the M2MS-AL has internal mirrors for wavelengths between 250 - 600 nm. A magnetic mount at the input port allows the included AR-coated lenses (see boxes below) to be easily switched out to optimize the system for your laser source.
The beam profiler and focusing lens remain in a fixed position. For M2 measurements, the beam path length is varied using a movable retroreflector mounted on a DDSM100/M translation stage, which has a translation range of 200 mm and a maximum velocity of 500 mm/s.
Thorlabs' M2 Measurement Systems provide self-contained, turn-key solutions for measuring M2, divergence, focus diameter, waist position, Rayleigh length and other laser beam quality metrics. Pre-configured, factory-aligned systems covering wavelength ranges between 250 nm and 2700 nm are available. Choose from among systems that have a scanning-slit beam profiler, a camera beam profiler, or no beam profiler. Each system includes a set of lenses, an alignment laser, and a variety of accessories. Configuration options are outlined in the table below.
The M2 factor, also called the beam quality factor or the beam propagation factor, is a measure of the quality of a beam. This parameter is defined as the ratio of the beam parameter product (waist size times the far-field divergence angle) of a laser beam to that of a diffraction-limited Gaussian beam at the same wavelength. A value of 1 is indicative of a pure TEM00 beam (or a diffraction-limited beam). Higher values imply that a beam is not strictly a TEM00 beam. Please see the product manual for more details on the M2 parameter.
Thorlabs' fiber-based, compact, Czerny-Turner CCD spectrometers are available in three models. Two are sub-nanometer accuracy models that provide detection in the 350 - 700 nm or 500 - 1000 nm range. A third model offers a wide 200 - 1000 nm spectral range with better than 2 nm accuracy. With a footprint that measures roughly the size of a portable hard drive (122 mm x 79 mm x 29.5 mm), the performance of these CCD spectrometers is ideal for educational applications or fiber-based systems. Each unit comes amplitude corrected and is shipped with a calibration report.
Although small, the unit shares features with larger, more expensive spectrometers such as the ability to be synchronized via a TTL trigger input (up to 100 Hz) and to automatically compensate for noise created by dark current. The three models share the same design with the CCD chips, gratings, and lenses being optimized for the specified wavelength range.