Beam analysis with HASO™ as a complement to your beam profiler Customers that work with lasers know how important it is to have a properly aligned optical system to optimize the efficiency of their beam. In this technology note, we’ll explain why HASO Shack-Hartmann wavefront sensors are an ideal complement to your beam profiler. Beam profilers are excellent, inexpensive tools for measuring the intensity of your laser at a very high spatial resolution. While they are extremely useful, the fact that they only measure intensity means that the data you rely on to perfect your beam is limited to the consequences of its imperfections rather than the causes behind them. In contrast to beam profilers, HASO wavefront sensors use a wealth of patented technologies to measure your beam’s phase and intensity, simultaneously and independently. This functionality, unique to HASO, provides you with information on the beam’s geometric parameters and propagation as well as on the perturbations it’s undergone. The data you acquire allows you to understand the beam’s evolution over time and space, and to determine where the problem is in your assembly in order to correct it quickly.

HASO™ Shack-Hartmann technology provides information both beam intensity and phase. When you rely solely on the measurements furnished by a beam profiler, you can find yourself with a lot of guess work in order to get your beam up to peak performance, transforming what may often be a rapid correction into a long and arduous procedure. What’s more, when you only measure intensity, you’re never 100% sure that you’ve gotten your beam up to its full potential. While, as we said, beam profilers are excellent tools, the inherent limitations of their technology also limit their effectiveness. In situations...

The preceding illustration shows that by combining the independent measurements of the beam’s phase and intensity, HASO determines its M² parameter. This allows you to determine the beam’s form anywhere in space, the position and shape of its waist, its divergence over distance, and its angular size. What makes HASO wavefront sensors unique and what does that mean to you? Imagine Optic’s HASO wavefront sensors are based on the Shack-Hartmann technique for wavefront sensing (to learn more about this technology, please see the introduction and related documents on www. imagine-optic.com). The HASO...

into providing false measurements. In short, performing both measurements at the same time, yet keeping them independent, provides you with precise information on the state of you beam that you can use in a variety of ways. First, you can compare your beam’s actual wavefront intensity and phase versus its best theoretical performance. This can help you work better and to save time by deciding for yourself what the optimal beam quality is to meet your individual needs. HASO equally allows you to analyze your beam’s performance over time to identify progressive or evolutionary variations via a...

Modal reconstruction allows you to quantify aberrations in your beam and compare it to known polynomials via a software simulation interface. This mode is ideal for exporting data for reports and publications and only HASOv3 incorporates certain unique features into its circumscribed or inscribed pupil definition options. When you choose to work with a circumscribed pupil, HASOv3 provides the unique, real-time (image to the far left below) ability to detect the radius around your beam’s entire pupil and, by eliminating measurement points with no signal, provides you with its true form. When you...