SLM, narrow linewidth, coherence
MSL-III-638L is a 638 nm Single-Frequency laser. Used for raman spectroscopy, speckle interferometry, bio-instrumentation, metrology. Spectral linewidth <100 MHz. Key specifications: output / average power 1~40 mW, operating mode CW, power stability (rms, 4 hours ± 3°c) <2%, <1%, <0.5%. View specifications, datasheet and enquiry options from Precisometer.
Specifications
21 specification rows
| Output / average power | 1~40 mW |
|---|---|
| Beam / notes | Spectral linewidth <100 MHz |
| Operating mode | CW |
| Power stability (rms, 4 hours ± 3°C) | <2%, <1%, <0.5% |
| Transverse mode | Near TEM00 |
| Longitudinal mode | Single |
| Spectral line width (MHz) | <100, (<50 optional) |
| Noise of amplitude (rms, 20Hz-20MHz) | <1%, <0.5% |
| M2 | <1.5 |
| Beam divergence, full angle (mrad) | <1.2 |
| Warm-up time (minutes) | <5 |
| Operating temperature (℃) | 10-35 |
| Power supply (100-240VAC) | PSU-III-FDA |
| Expected lifetime (hours) | >10000 |
| Central wavelength (nm) | 638±0.5 |
| Output power (mW) | 1-40 |
| Coherent length (m) | >2 |
| M² | <1.5 |
| Beam diameter at the aperture (1/e2, mm) | <3 |
| Polarization ratio | >50:1, (>100:1 optional) Horizontal±5 degree (Vertical optional) |
| Beam height from base plate (mm) | 24.8 |
Application context
Applications named on this model’s datasheet, expanded with the model’s optical specifications.
MSL-III-638L: 638 nm emission sets the excitation and detector-band choice for Raman spectroscopy; linewidth and wavelength stability determine how cleanly weak spectral features can be separated from the laser line. The listed beam characteristic (Near TEM00) also controls focusing and collection geometry.
MSL-III-638L: Speckle interferometry benefits from a stable, focusable source. 638 nm emission fixes the compatible coatings and detector response, while the listed beam characteristic (Near TEM00) informs waist size and propagation.
MSL-III-638L: 638 nm emission determines compatible optics, coatings and detectors for Bio-instrumentation. The catalogued beam parameter (Near TEM00) helps predict how the source will focus and propagate through the instrument.
MSL-III-638L: 638 nm emission determines compatible optics, coatings and detectors for Metrology. The catalogued beam parameter (Near TEM00) helps predict how the source will focus and propagate through the instrument.
System integration
Use these checks to connect MSL-III-638L to the surrounding optical, mechanical and control system. Every value shown is taken from this model's own specification record.
Technical FAQ
Operating temperature (℃): 10-35. Provide the stated cooling method and keep the laser-head base thermally coupled; temperature drift moves wavelength, output power and beam pointing.
Transverse mode: Near TEM00 · M2: <1.5. Size the downstream optics from the stated beam diameter and divergence rather than from the aperture of the housing, and confirm the polarisation state before specifying isolators or polarising optics.
Share wavelength, operating mode, output power or pulse energy, linewidth or pulse width, delivery, control, and safety requirements and we will qualify the matching configuration and lead time.
Model selection
Compare MSL-III-638L with the closest available models in the Single-Frequency Lasers family. Confirm option-dependent values on the final configuration before ordering.
| Selection parameter | MSL-III-638L (current) | 6 3 8 | Narrow Linewidth |
|---|---|---|---|
| Wavelength | 638 nm | 638 nm | 637 nm |
| Optical power / pulse energy | 1~40 mW | 1~40 mW | 1-50 mW |
| Operating mode / pulse width | CW | Confirm for this model | Confirm for this model |
| Beam quality | Near TEM00 | <1.5 | Confirm for this model |
Compare the MSL-III-638L with nearby single-frequency lasers across the wavelength range.
Choosing a laser
Which specifications decide the experiment, and which ones cost money without changing the result.
PhotonicsLinewidth, spectral width, RIN, M², and coherence length answer five different questions. Translate each into the units your experiment is designed in — and learn which ones not to pay for.
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PhotonicsSingle-mode fiber does not preserve polarization. Pin the state, erase it with a scrambler, or maintain it in PM fiber — which one your measurement needs, and the response time and extinction ratio that decide it.
Open guide