Introduction

　　A Beam Splitter of Beijing HOMOlaser S&T CO., Ltd is a diffractive optical element (DOE) used to split a single laser beam into several beams, each with the characteristics of the original beam (except for power and angle of propagation). A beam splitter can generate either a 1-dimensional beam array (1xN) or a 2-dimensional beam matrix (MxN). The figure below shows a 32*32 splitted beam, taken from actual items. Based on that, a common variation of the laser beam splitter / multi-spot DOE is a multi-line array, where instead of a 1xN array of spots, the user will get a 1xN array of lines, whose length and separation angle are determined during the design according to the customer's application requirements.

Applications

　　lLaser cutting

　　lLaser drilling

　　l3-D sensors

　　lLaser scribing

　　lFiber optics

　　Operation principle

　　In principle, A Beam Splitter demands a collimated input beam, the output beams exit from Beam Splitter DOE with a separation angle that is determined based on the customer's system requirements during the design of the DOE. The separation angle designed for far-field is highly accurate (<0.03mR error).

　　Homolaser is also able to design a custom beam splitter and so activate and deactivate any order of the beam splitter.

　　Normally, the customer wishes to get well-focused spots at a certain distance. This is easily achieved by the addition of a simple focusing lens after the DOE, whose BFL (back focal length) determines the working distance (WD) to the multi-spot focal plane.

　　Characteristics

　　In double-spot configuration, power efficiency can reach nearly 80% due to physical constraints, while the multi-spot (>2) configurations can reach nearly 85% in binary etching process, and nearly 95% in multi-level etching. The remaining power is distributed among the other (parasitic) orders.

　　In order to obtain an ideal performance, it is recommended for our customers to provide the input beam size, which is at least 3-5 times the period of the pattern on the DOE, 5 times better.

　　Design consideration

　　Design considerations according to customers’ demand：laser wavelength，beam size, focal length of the focusing lens (if needed), and the diffraction angles.

　　Notification