Diffractive Optical Elements (DOEs)

Beam Splitter DOEs
Beam Shaper DOEs

Beam Splitter DOEs

Part No.	Wavelength (nm)	Dia (mm)	Thickness (mm)	Separation Angle	No. of Spots
DOE-355-1x3 *NEW*	355	25.4	3	0.0053˚	3
DOE-355-1x4 *NEW*	355	25.4	3	0.048˚	4
DOE-355-1x8 *NEW*	355	25.4	3	0.048˚	8
DOE-532-1x8 *NEW*	532	25.4	3	0.323/0.232/0.224˚	8
DOE-1064-1x4 *NEW*	1064	15.0	3	1.15˚	4
DOE-1064-1x8 *NEW*	1064	25.4	3	0.646/0.464/0.449˚	8

Beam Shaper DOEs

Part Number	Wavelength (nm)	F-theta EFL (mm)	Dimension (mm)	Input Beam Dia(mm)	Flat Tope Beam Size (µm)
DOE-SCAN-1064-254C	1064	254	16 x 16 x 3	4.5	116
DOE-SCAN-1064-163	1064	163	16 x 16 x 3	5.0	118
DOE-SCAN-532-330	532	330	16 x 16 x 3	3.0	120

Beam Splitter DOEs

The collimated laser light is incident onto an array (1 x N or M x N) of Beam Splitter DOE to split the input beam into N beams. The N output beams make some separation angle with the Beam Splitter DOE and there exists the desired zero-order beam for an odd number of beams (N). The focusing lenses are often used to achieve the output at the desired working distance.

Beam Shaper DOEs

This setup comprises a laser source, Beam Shaper DOE, scan system/lens, and a working surface. The light passed through the Beam Shaper DOE distributes the Gaussian beam energy into a uniform intensity of either a circular or rectangular top-hat profile.

Beam Splitter DOEs

Material: Fused Silica
Beam Mode: SM or MM
Separation Angle: ≤ 5°
Transmission Efficiency: ̴ 100%Overall Efficiency ̴ 74- 85%
Uniformity (Contrast): < 1-3%
Zero-Order: relative to the incident beam<0.5-1%
Type: Window
Coating: AR/AR @ 355nm, 532nm, 1064nm

Beam Shaper DOEs

Material: Fused Silica
Beam Mode: SM or TEM ₀₀ with M²<1.5
Transmission Efficiency: ̴ 100%
Overall Efficiency: ̴ 90-95%
Shape: Circular, Rectangular
Type: Window
Coating: AR/AR @ 532nm, 1064nm

Beam Splitter DOEs

Beam Shaper DOEs

Laser Processing

Diffractive Optical Elements (DOE): Beam Splitter & Shaper Application Note

Author: Vincent

Beam Splitter & Shaper: Modifying lasers through diffraction

DOE technologies are emerging in the optics industry. Its applications range from technical optics such as scanning and metrology to bioimaging and printing. DOEs are added to laser systems to control the incident beam’s phase and amplitude and to ‘shape’ the beam to a desired output pattern with distinctive functionality. It uses a surface complex microstructure to direct photons for specific functions.

Operation Principle

A DOE beam splitter is used to split a collimated incident beam into multiple beams. The power is shared between the resultant beams. These beams form a 1xN array (1-dimension) or MxN array (2- dimension) depending on the setup. Resultant beams exit the beam splitter with separation angle θ (Figure 1). For an odd number of beams (N), there is a desired beam that falls on the 0-order. For an even number of beams, there is no beam on the 0-order. To achieve well-defined spots at the desired working distance, focusing lenses are often used, as seen in Figures 1 and 2.

Series Module	DOE-355-1×3	DOE-355-1X4
Wavelength*	355nm	355nm
Beam Mode	SM or MM	SM or MM
Number of Spots*	1×3	1×4

Table 1. Specifications of Beam Splitter

*DOE can be customized to a preferred wavelength, spot size, focal length, and divergent angle of the beam.

A DOE beam shaper setup typically consists of a laser, a DOE beam shaper, a scan system/lens, and the working surface (Figure 3). The beam shaper DOE distributes the energy of a Gaussian beam spot to a Top-Hat profile with uniform intensity. This ensures an even laser irradiation on the working surface. The top-hat profile is identified by a sharp transition area that generates a clear boundary between treated and untreated regions. The output profile can either be rectangular or circular, (Figure 4).

Figure 4. Output profile (rectangular/circular) after beam shaping

Series Module	DOE-9.4-150×200	DOE-SCAN-1064-163
Beam Mode	SM TEM00 with M2 < 1.5	SM TEM00 with M2 < 1.5
Element Type	Window	Window
Shape	Rectangular	Circular

Table 2. Specifications of Beam Shaper

Applications

Being able to modify and isolate the resultant beam has proved useful in uses such as scanning the surface of the skin or implementing perforation on cigarette filters.

The systems could be used in, but not limited to the following application scenarios: