Beam Expander Selection Guide

In many laser based applications, beam expanders are an essential component of the optical system. They are most often used to decrease divergence or to create smaller final focused spot sizes by expanding the beam before the final focusing element. They are also used to increase beam diameter, therefore reducing power density or facilitating alignment.

Once you have determined the need for a beam expander, selecting the correct beam expander can be a daunting task due to the numerous options available. The table below displays a selection guide for determining which Edmund Optics^® (EO) beam expander will best fit your application.

TECHSPEC^® Beam Expanders (Table 1 of 2)
	Expansion Power
	1X	2X	3X	4X	5X	6X	7X	8X	10X	15X	20X
Scorpii Nd:YAG
Vega Laser Line
Vega Broadband
Arcturus HeNe
Draconis Laser Line
Draconis Broadband
RVBX Option #1	Variable
RVBX Option #2		Variable

TECHSPEC^® Beam Expanders (Table 2 of 2)
	Design Wavelength (nm)	Transmitted Wavefront, P-V	Entrance Aperture (mm)	Mount	Focusing Mechanism	Price per Piece
Scorpii Nd:YAG	355, 532, 1064	λ/4 @ DWL	3.5 – 5	M22 x 0.75	None	$
Vega Laser Line	266, 355, 532, 1064	λ/10 @ DWL	7.5 – 10	M30 x 1	Rotating Optics	$$
Vega Broadband	250 – 532, 500 – 1090, 1030 - 1550, 1900 – 2100	λ/10 @ DWL	4.5 – 10	M30 x 1	Rotating Optics	$$
Arcturus HeNe	633	λ/4 @ DWL	2	C-Mount	Sliding Optics	$$$
Draconis Laser Line	532, 1064	λ/10 @ DWL	8 – 11	C-Mount	Sliding Optics	$$$$
Draconis Broadband	260 – 365, 425 – 700, 500 – 1100, 750 – 1100	λ/10 @ DWL	8 – 11	C-Mount	Sliding Optics	$$$$
RVBX Option #1	266, 355, 532, 1064, 260 – 365, 425 – 700, 500 – 1100, 750 – 1100	λ/4 @ DWL	10 – 15	C-Mount	Sliding Optics	$$$$$
RVBX Option #2	355, 532, 1064, 260 – 365, 425 – 700, 500 – 1100, 750 – 1100	λ/4 @ DWL	10 – 15	C-Mount	Sliding Optics	$$$$$

Tables 1 and 2: Selecting the right beam expander for your application requires knowledge of many different parameters. Edmund Optics offers a variety of beam expanders with different specifications, sizes, and prices to best fit your application requirements.

The first step is determining whether fixed or variable magnification is required. For variable magnification applications, EO offers the Research-Grade Variable Beam Expanders (RVBX).

For fixed magnification applications, the laser wavelength, input aperture, and required transmitted wavefront performance must first be determined. For cost sensitive applications at Nd:YAG wavelengths, EO offers Scorpii Nd:YAG Beam Expanders. These beam expanders have an entirely fixed optical design and offer diffraction limited performance for Nd:YAG fundamental wavelengths, first harmonics, and second harmonics.

For applications where divergence adjustment is required to collimate converging or diverging input beams, or alternatively to create a controlled, slightly convergent or divergent output, Vega and Draconis Fixed Beam Expanders are the best choice. For Nd:YAG wavelengths, the ideal options are the Vega Laser Line Beam Expanders and Draconis Laser Line Beam Expanders. The Vega Laser Line Beam Expanders offer excellent value, with λ/10 performance, coatings for Nd:YAG wavelengths up to the third harmonic, and input apertures up to 10mm. Compared to the Vega Laser Line Beam Expanders, the Draconis Laser Line Beam Expanders are the premium option due to their sliding optics and larger apertures.

The Arcturus HeNe Beam Expanders are designed specifically for use with HeNe lasers, and feature sliding optics in divergence adjustment for relatively small apertures up to 2mm. The UDA Broadband Fixed Beam Expanders are designed for broadband use, offering a selection of broadband coatings covering 260 – 1100nm, sliding optics for divergence adjustment, and λ/10 performance at their design wavelength.

The decision tree below provides a visual method of determining which Edmund Optics beam expander meets your application requirements.

		Start Here What Beam Expander do I need?

YES	Do I need to be able to change my magnification?		No

RVBX

YES	Do I need to be able to Adjust for divergence/focus?		No

				Scorpii Nd:YAG

OTHER / BROADBAND	What Laser am I using?		HeNe

Draconis Broadband	Nd:YAG or Nd:YLF		Arcturus HeNe

YES	Do I Need Sliding Optics or Large Apertures		No

Draconis Laser Line			Vega Laser Line

When standard or stock options do not meet your criteria, custom versions can be designed. Some custom requirements allow for quick modifications on standard beam expander designs, allowing for a rapid, cost-effective turnaround. Contact us to discuss your specific requirements with one of our Application Support Engineers.