Focus spot size and position monitor for high power lasers

With no contact with the laser beam, the system has no power restriction: it has been successfully tested on high power lasers up to 100kW. This updated verison now offers an algorithm to optimise the measurement window, removing imprecise, manual judgments from the process and improving the overall precision of measurements.

While conventional measurement systems place a probe in the beam, causing potential damage and slowing the measurement process (it could take up to two minutes to gather data and characterise the beam); Ophir Photonics have claimed that BeamWatch is the industry's first laser monitoring system to instantly and accurately measure laser parameters without requiring contact with the laser beam. Measuring the Rayleigh scatter caused by the beam, the system makes a set of complete measurements at camera update rates. This provides instant readings of focus spot size and beam position, as well as dynamic measurements of focal plane location during process start-up.

Monitoring high power YAG, disc, fibre and diode lasers in the 980-1080nm range, BeamWatch measures the beam at frequent intervals without having to shut down the process or remove extensive tooling and fixtures. It measures focal spot location at 60ms intervals to indicate whether focal spot shifts are occurring during critical start-up moments.

BeamWatch features Technician and Operator Mode interfaces: Technician Mode provides access to the tools needed for start-up and advanced beam diagnostics, such as optimising measurement parameters or establishing pass/fail criteria; while in Operator Mode, the run-time interface displays measurements at video rates. Additionally, graphic displays help operators quickly understand the status of the laser’s performance without having to interact with the laser or the monitoring system.