The Thorlabs PM140 is a handheld optical power meter engineered for precise laser measurements at 400 nm wavelength. Its integrating sphere sensor with silicon detector delivers measurement accuracy largely independent of beam shape and entrance angle, making it exceptionally suited for highly divergent beams from optical fibers and higher power applications.
Technical Specifications
• Wavelength Range: 400 nm to 1100 nm
• Power Range: 1 µW to 1 W
• Measurement Units: dB, dBm, Watt
• Accuracy: ±5%
• Max Power Density (CW): 10 W/cm² (50 W/cm² with ND Filter)
• Measurement Standard: NIST Traceable
• Sensor Dimensions: 150 × 19 × 10 mm
• Aperture: Ø9.5 mm
• Distance to Detector: 3.3 mm
• Distance to ND Filter: 1.2 mm
• Sensor Weight: 200 g (with connector)
• Operating Temperature: 5°C to 40°C
• Storage Temperature: -20°C to 70°C
– Key Features
• Integrating sphere sensor minimizes beam shape and angle dependencies for improved measurement consistency
• Digital display with user-selectable views: numerical, bar graph, trend graph, statistics, and simulated analog needle
• Data logging capability with .csv export functionality
• USB 2.0 connectivity for PC control via Thorlabs Optical Power Monitor software
• Analog output: 0 to 2 V signal corresponding to measured value ratio to full scale
• Compact, portable handheld design
• Two sets of #8-32 and M4 threaded mounting holes for standard post integration
– Typical Applications
• Fiber-coupled laser beam power measurement
• Divergent beam characterization
• High-power optical applications requiring dynamic range from 1 µW to 1 W
• Laboratory and field power monitoring across UV-to-near-IR spectral range
– Compatibility & Integration
The PM140 display unit pairs with S140A integrating sphere sensors. Standard fiber adapters supported include FC (supplied), ST, SC, bare fiber, and SMA configurations. Thorlabs Optical Parameter Monitor (OPM) software enables remote control and monitoring via USB interface.
