LENSES
The lens is the key optical component for CO2 -laser-based units. Due to its curved shape it allows to transform incident collimated beam into tinysize area and thus concentrate the entire power of laser source in the shape of a spot. LENSES Plano-convex lenses are the most economical transmissive focusing elements. Its prime advantage is the lower cost, whereas meniscus lenses can provide better performance, since they are specifically designed to minimize spherical aberration.The lenses of both designs can be effectively
utilized for CO 2 -laser-based heatreating, welding, cutting, drilling, and marking apparatuses. Besides the plano-convex and meniscus lens shapes already mentioned, Tydex supplies biconvex and cylindrical lenses. Custom-made lenses are manufactured upon request. Zinc Selenide, Gallium Arsenide, and Potassium Chloride can be used for production of lenses. Standard ZnSe and GaAs lenses are offered with both surfaces AR coating at 10.6 m. KCl lenses are supplied uncoated.
Plano-Convex Lenses
Specifications:
1.
Material:
CVD-ZnSe, GaAs, KCl*
2.
Effective focal length (EFL) tolerance, %:
+/- 2
3.
Diameter tolerance, mm:
+0.0 / -0.1
4.
Thickness tolerance, mm:
+/- 0.25
5.
Edge thickness variation (ETV), mm:
<= 0.05
6.
Clear aperture:
90% of diameter
7.
Surface figure (power-irregularity) @ 633 nm:
plano, fringe:
1 - 1/2
radiused:
depends on radius
8.
Surface quality, scr/dig:
40/20
9.
AR coating reflectivity per surface
@ 10.6 µm, %:< 0.5
BBAR coatings are also available for NIR-MIR.
* KCl lenses are supplied uncoated.
Meniscus Lenses
Specifications:
1.
Material:
CVD-ZnSe, GaAs
2.
Effective focal length (EFL) tolerance, %:
+/- 2
3.
Diameter tolerance, mm:
+0.0 / -0.1
4.
Thickness tolerance, mm:
+/- 0.25
5.
Edge thickness variation, mm:
<= 0.05
6.
Clear aperture:
90% of diameter
7.
Surface quality, scr/dig:
40/20
8.
Surface figure (power-irregularity)
@ 633 nm:varies dependent upon radius
9.
AR Coating reflectivity per surface
@ 10.6 µm, %:< 0.5
The plano-convex lenses and meniscus lenses of the following sizes are available from stock:
BBAR coatings are also available for NIR-MIR.
Standard sizes:
Diameter
EFL
inches
mm
inches
mm
0.50
12.7
1.00
25.4
0.75
19.1
1.50
38.1
1.00
25.4
2.50
63.5
1.00
25.4
3.75
95.3
1.00
25.4
5.00
127.0
1.00
25.4
10.00
254.0
1.10
27.9
2.50
63.5
1.10
27.9
3.75
93.5
1.10
27.9
5.00
127.0
1.10
27.9
7.50
190.5
1.50
38.1
2.50
63.5
1.50
38.1
3.50
88.9
1.50
38.1
5.00
127.0
1.50
38.1
7.50
190.5
2.00
50.8
5.00
127.0
2.50
63.5
5.00
127.0
2.50
63.5
10.00
254.0
3.00
76.2
5.00
127.0
3.00
76.2
10.00
254.0
Cylindrical Lenses
Specifications:
1.
Material:
CVD-ZnSe
2.
Effective focal length tolerance, %:
+/- 2
3.
Diameter (width & length) tolerances, mm:
+0.0 / -0.1
4.
Thickness tolerance, mm:
+/- 0.25
5.
Edge thickness variation, mm:
<= 0.05
6.
Clear aperture:
> 85% of a size
7.
Surface figure (power-irregularity) @ 633 nm:
plano, fringe:
1 - 1/2
radiused:
depends on radius
8.
Surface quality, scr/dig:
60/40
9.
AR Coating reflectivity per surface
@ 10.6 µm, %:< 0.5
BBAR coatings are also available for NIR-MIR.
Custom-Made Lenses
Dual-focus lens
Dual-focus lenses (DFL) are a revolutionary new type of lens for CO2 laser cutting.
DFL are intended to be used as a direct replacement for conventional lenses in some industrial laser systems and applications. The basic principal of the lenses coming from their title lies in existence of a couple of focal points. Complex design of these lenses allows to distribute an incident laser energy and deliver its calculated fraction into a secondary (lower) focus.
Especially designed to assist in a range of thick-section cutting jobs such lenses give the followings advantages:
processing of increased thicknesses at a given power
increased process speed
improved kerf quality
elimination of upper and lower surface dross
immediate cut-initiation
reduced assist-gas usage
improved process control
Tydex proposed and has been using a novel approach in fabrication of DFL, which in particular did allow us to create DFL of cylindrical shape.
A specification below presents standard product. Custom-made sizes and specifications are available as well. Non-standard lenses can be designed and proposed upon certain RFQ.
Specifications:
1.
Type of a part:
cylindrical dual-focus lens
2.
Material:
CVD-ZnSe
3.
Overall dimensions, mm:
25.4 (+0/-0.25) x 25.4 (+0/-0.25)
4.
Thickness, mm:
4.0 (+0.5/-0.0)
5.
Radii of curvature:
the values depend on required combination of EFL
6.
EFL tolerance @ 10.6 µm, %:
+/- 2
7.
Stripe width, mm:
4 (+0.5/-0)
8.
Surfaces quality, scr/dig:
60/40
9.
Surface figure, fringe:
8
10.
AR Coating reflectivity per surface
10.6 µm, %:< 0.5
Fig. 1 Cylindrical DFL working principle.
Tydex supplies cylindrical DFL with the following EFL combinations: 127 & 254 mm, 169 & 254 mm.