Nominal values for peak-to-valley wavefront error

Features

Surface Quality: 20-10 (Scratch-Dig)
Wavefront Error: <λ/4
Damage Threshold: 100 W/cm² CW
AR Coating: R_avg<0.5% Over Coating Range

The BE series of Galilean Beam Expanders is available with either a 2X - 5X or a 5X - 10X continuously variable beam expansion ratio. For the 2X - 5X zoom models, the expansion ratio can be adjusted from the minimum to the maximum value via one full rotation of the zoom control. Once the desired magnification is obtained, a setscrew can be tightened to lock the magnification. For the 5X - 10X zoom models, minimum to maximum expansion adjustment is achieved with only half of a rotation of the zoom control. For all models, if the beam exiting the expander is collimated and the magnification is changed, the focus should be readjusted to maintain collimation. Please note that the induced wavefront error varies with the magnification ratio. This wavefront error can be seen in the graph to the right.

Our variable beam expanders are offered with a broadband antireflection coating for the 400 - 650 nm (-A), 650 - 1050 nm (-B), or 1050 - 1620 nm (-C) range. These units also feature achromatic operation over the specified AR coating range. The input lens can also be rotated to adjust the distance between the input and output lenses in order to compensate for the divergence or convergence of the output beam. Each beam expander features SM-threaded input and output ports (see the table below for details), making them compatible with a number of Thorlabs components such as lens tubes.

Thorlabs also offers many other types of beam expanders, including fixed beam expanders whose expansion ratio is achieved via either a rotating or sliding adjustment mechanism. For more information on our extensive line of beam expanders, please click on the Selection Guide tab.

Item #	Expansion	Input Aperture	Max Input Beam Diameter (1/e²)	Input Threading	Output Threading	Mounting Holes	AR Coating Range
BE02-05-A	2X - 5X	Ø8.0 mm	Ø4.0 mm	SM1 (1.035"-40)	SM2 (2.035"-40)	8-32 (M4)	400 - 650 nm
BE02-05-B	2X - 5X	Ø8.0 mm	Ø4.0 mm	SM1 (1.035"-40)	SM2 (2.035"-40)	8-32 (M4)	650 - 1050 nm
BE02-05-C	2X - 5X	Ø8.0 mm	Ø4.0 mm	SM1 (1.035"-40)	SM2 (2.035"-40)	8-32 (M4)	1050 - 1620 nm
BE05-10-A	5X - 10X	Ø8.0 mm	Ø2.3 mm	SM05 (0.535"-40) and SM2 (2.035"-40)	SM2 (2.035"-40)	1/4"-20 (M6)	400 - 650 nm
BE05-10-B	5X - 10X	Ø8.0 mm	Ø2.3 mm	SM05 (0.535"-40) and SM2 (2.035"-40)	SM2 (2.035"-40)	1/4"-20 (M6)	650 - 1050 nm
BE05-10-C	5X - 10X	Ø8.0 mm	Ø2.3 mm	SM05 (0.535"-40) and SM2 (2.035"-40)	SM2 (2.035"-40)	1/4"-20 (M6)	1050 - 1620 nm

Item #	Lens Substrates
BE02-05-A	N-BK7, SF2, N-FK5, SF5
BE02-05-B	BAFN10, SFL6, N-FK5, LAKN22
BE02-05-C	BAFN10, SFL6, N-FK5, LAKN22

Item #	Lens Substrates
BE05-10-A	N-BK7, SF2
BE05-10-B	BAFN10, SFL6,N-BK7, LAKN22
BE05-10-C	BAFN10, SFL6, N-BK7

Thorlabs offers several different families of beam expanders to meet various experimental needs. The table below provides a direct comparison of the options we offer. Please feel free to call one of our applications engineers if you would like help choosing the best beam expander for your specific application.

Specification	ELU Series	EL Series	ELQ Series	BE Series (Fixed)	BE Series (Variable, Rotation)	BE Series (Variable, Sliding)	BE Series (Reflective)
Expansions Available	2.5X, 5X, 10X, 20X	2.5X, 3X, 5X, 10X, 20X	2.5X, 5X, 10X, 20X	2X, 3X, 5X, 10X, 15X, 20X	2-5X 5-10X	0.5 - 2X	2X, 4X
Collimation Adjustment Mechanism	Sliding			Rotation		Sliding	Fixed
AR Coating Range(s) Available	248 nm 351 nm	400 - 650 nm 650 - 1050 nm 1050 - 1620 nm 3000 - 5000 nm	1064 ± 40 nm	400 - 650 nm 650 - 1050 nm 1050 - 1620 nm		400 - 650 nm 650 - 1050 nm	None
Mirror Coating (Range)	None						Silver (450 nm - 20 μm)
Average Reflectivity (per Surface)	<0.2%	<2%	<0.2%	<0.5%		<0.5%	>96%
Max Input Beam Diameter (1/e²)^a	2.5X: Ø4.4 mm 5X: Ø2.2 mm 10X: Ø1.1 mm 20X: Ø0.6 mm	2.5X: Ø4.4 mm 3X: Ø4.0 mm 5X: Ø2.2 mm 10X: Ø1.1 mm 20X: Ø0.6 mm	2.5X: Ø4.4 mm 5X: Ø2.2 mm 10X: Ø1.1 mm 20X: Ø0.6 mm	2X, 3X: Ø4.0 mm 5X, 10X, 15X, 20X: Ø2.25 mm	Ø3.0 mm	0.5X: Ø6.0 mm to 2X: Ø3.0 mm	Ø3 mm
Input Aperture	2.5X: Ø9 mm 5X: Ø10.9 mm 10X: Ø9 or Ø10.9 mm 20X: Ø3.5 or Ø3.8 mm	2.5X: Ø9 or Ø11.0 mm 3X: Ø11.0 mm 5X: Ø10.9 mm 10X: Ø9 or Ø10.9 mm 20X: Ø3.5 mm	2.5X: Ø11 mm 5X, 10X: Ø10.9 mm 20X: Ø3.5 mm	2X, 3X: Ø8 mm 5X, 10X, 15X, 20X: Ø4.5 mm	Ø8.0 mm	Ø10.0 mm	Ø6 mm
Wavefront Error	<λ/4						<λ/10^b
Scratch-Dig	10-5 (20-10 for -E Coating)			20-10			40-20
Optics	Two Best-Form or Spherical Lenses			One Plano-Concave Singlet, One Doublet	Spherical Singlets and Doublets		Two Spherical Mirrors

^aFor Diffraction-Limited Performance
^b Ø1.5 mm Input Beam for BE02R and Ø1 mm Input Beam for BE04R

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Posted Comments:

Poster: cdaly

Posted Date: 2012-11-30 16:24:02.953

Response from Chris at Thorlabs: Thank you for using our feedback feature. We are unable to provide 2010 SolidWorks files directly as the version we use for design (2012) restricts us from creating backwards compatible files, but we do have Step files available for download as well. These files can be opened in SolidWorks 2010 and then saved as an .sldprt file, which will give you the format you require.

Poster: xiaoqiang026403

Posted Date: 2012-11-29 02:15:44.87

I use SolidWorks 2010,but some of your products' Drawing and Documents (SolidWorks) are opened by SolidWorks 2012. Could you send me the BE02-05-A SolidWorks Documents in version 2010?

Poster: jlow

Posted Date: 2012-11-06 09:39:00.0

Response from Jeremy at Thorlabs: We ran a simulation in Zemax and found that the performance is pretty much the same for the BE05-10-C and using doublet. If you do not need the zoom function, I would recommend using a fixed magnification because the cost is generally lower.

Poster: neil.troy

Posted Date: 2012-10-18 22:55:46.787

What is likely to be the performance for these systems with broad light sources, say 100 nm wide? If I could live with a fixed lens magnification would I be better off with using a pair of appropriately chosen achromatic doublets?

Poster: bdada

Posted Date: 2012-02-24 14:52:00.0

Response from Buki at Thorlabs.com to omertzang: Thank you for your feedback. We do not have any specific data on the damage threshold for pulsed light but we expect the beam expander to withstand 100 mJ/cm2 if the pulse is 10 ns. Pleae contact TechSupport@thorlabs.com if you have any questions.

Poster: omertzang

Posted Date: 2012-02-05 06:04:13.0

I could not find the damage threshold for Pulsed laser. please send me the damage threshold specification for pluses. I intend to use a 800nm femto-second Ti-Sapphire and I am sure your costumers have experience in a beam expansion setup for such lasers. Thank you!

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