LASER TEST & MEASUREMENT APPLICATIONS

Laser Test applications involve the measurement of optical power or energy at a specific laser wavelength.  A single laser pulse contains a certain amount of energy, measured in joules (J).  A repetitively-pulsed laser transmits this energy in a pulse train at a certain rate; the rate of energy transfer is the average power, measured in watts, where one watt (W) equals one joule per second (J/s).  Similarly, a continuous-wave (CW) laser has a continuous power output, also measured in watts.

Critical laser characteristics, or operational parameters, include:

• Laser Wavelength(s)
• Power/Energy
• Beam characteristics:
  • Beam diameter
  • Divergence
  • Polarization
• Temporal characteristics:
  • CW/Single-Shot/Repetitively-Pulsed
  • Pulse width
  • Pulse rate

Measurement system selection: The laser characteristics listed above guide the specification of an appropriate measurement system: 

• Sensor Type:
  • Silicon (Si)
  • Filtered Silicon
  • Germanium (Ge)
  • Indium-Gallium-Arsenide (InGaAs)
• Attenuator Type:
  • Integrating Sphere
  • Simple Diffuser
• Attenuator Design:
  • Aperture Diameter
  • Sphere Size
  • Diffuser Transmittance

For example, an integrating sphere reduces sensitivity to beam polarization and alignment, and can accommodate large or divergent beams, while a simple diffuser is smaller, and offers greater sensitivity for low-power applications.  Larger spheres offer greater attenuation for higher-power applications, avoiding sensor saturation; smaller spheres offer greater efficiency at lower power.

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UDT Instruments offers a range of complete, pre-configured solutions to meet the most common laser test and measurement requirements. Specialized configurations, and custom designs are also available.