The UDT Instruments division of Gamma Scientific offers solutions for measuring the optical power of lasers and laser diodes operating at wavelengths in the UV-VIS-NIR range (350 nm – 1800 nm) and at low to medium power levels (from < 10 nW to over 30W). Our laser-power measurement systems can also be configured to support “single-shot” energy measurements of individual laser pulses.
Laser Test and 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: 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: 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.
Laser Calibration Wavelengths
Gamma Scientific & UDTi offer calibrations at a choice of wavelengths for all of our laser power measurement systems. The standard calibration for any laser power meter is performed at a single wavelength selected from those listed in our table of standard calibration wavelengths. Custom calibration may be performed upon request at any other specified wavelength within the system’s nominal spectral range. Alternatively, UDTi/Gamma Scientific offer a standard multi-wavelength calibration, featuring several of the most common laser wavelengths (see table). For maximum flexibility, systems may be given a ‘continuous calibration’ at a regular wavelength interval over the full spectral range of the sensor.
Note that UDTi also offers several narrow bandpass filters, centered at common laser wavelengths, which can be added to a standard system in order to limit errors due to the contribution of ambient, heterogeneous stray light (light at wavelengths other than that of the device under test).
To simplify the selection of options available, we have defined a set of standard bundles, based on the Model 470 flexOptometer, which provide a sample of the laser test solutions available from UDTi. Some of our most popular offerings are presented below. For special applications, consult with our engineers about a custom solution.
FlexOptometer Radiometer/Photometer
High-performance optometer designed to operate as a stand-alone instrument or computer-controlled photometric, radiometric and fiber optic measurement system. Laboratory grade accuracy and durability ensures that the flexOptometer will operate in the most rigorous production line environments.
Laser measurement instrument system that combines a broadband silicon sensor with an integrating sphere to provide simple and accurate laser power measurements. The 150mm diameter sphere attenuates the beam to allow measurement of higher-power devices, reducing sensitivity to beam polarization and alignment. The sphere accepts beams of up to 19 mm (0.75″) diameter.
Laser measurement instrument system that combines a broadband silicon sensor with a multilayer diffuser-type laser power attenuator to provide simple and accurate laser power measurements. Maximum beam size is determined by the attenuator’s 7mm diameter aperture.
