ML-1 Polarization-Stabilized HeNe Laser
The ML-1 is a small, low cost laboratory HeNe laser. The ML-1 provides a linear-polarized, frequency-stabilized or intensity-stabilized, coherent, light source of continuous wave (CW) visible (red) laser light with a nominal output power of 1 mWatt. The ML-1 laser is ideal for laboratory measurements, spectroscopy, interferometery, and other sensitive distance measurements. The frequency of the ML-1 laser is stabilized and calibrated at the factory to provide an ideal light source wherever a visible calibrated light source is needed.
- Distance Measurement
- Interferometery (because the laser is unmodulated it can be used in interferometers with unequal arm lengths)
- Secondary standard reference
- Wavelength calibration (for other lasers)
- Alignment of optical systems
- Absolute gravimetery and gradiometry (requiring sub-nanometer distance resolution)
- Dual Stablized Modes
- Intensity Stabilized Mode: >0.01% over 1 hr.
- Frequency Stabilized Mode
- RMS Frequency Fluctuations (Measurement made with ML-1 locked to one side of gain curve):
- Short Term (10msec): <100 kHz (2×10-10)
- Long Term (days) (<1 °C room temp changes):<800kHz (2×10-9)
- Average of red/blue lock frequencies (stable room temperature): 500kHz/24hr or (f/f = 1×10-9/24hr
- Long-Term Power Drift: <1%
- Intensity Fluctuations:<0.1% (rms 1Hz-10MHz)
- Absolute accuracy measured and given to user upon delivery with an accuracy of better than 10MHz (2×10-8) Single Mode Purity: 1:500
- Frequency accuracy on side lock: 10MHz
- Output Beam Angular Drift: <1mrad
- After Warm-Up: <0.01mrad
- Warm-Up Time: Approx. 15min.
- Transverse Mode: TEMoo
- Beam Diameter at 1/e2: 0.63mm
- Beam Divergence: 1.3mrad
- Output Beam Polarization: Linear to >500:1
- Polarization Mode Purity: >500:1
- Frequency Lock Point: Select to red or blue side of line center
Shown below are two Allan Variances of the laser frequency when the ML1 is “beat” with an iodine-stabilized laser (primary standard frequency source). Each measurement occured over a 24 hour period. In the first case the room temperature cycled over 2 °C, while in the second case it was stable to better than 0.4 °C. Zero on the vertical axes is an arbitrary offset in the beat frequency between the two lasers.
A self-extracting SolidWorks® eDrawing can be downloaded here.
The dimensions of the housing are 13.0 x 3.5 x 3.5″, and the laser beam height is 2″ from the bottom of the feet.