Circular Precision Pinholes, Stainless Steel Foils, Vacuum Compatible


  • Pinhole Sizes from Ø5 μm to Ø2 mm
  • Stainless Steel Foils in Ø1" Stainless Steel
  • Physical Vapor Deposition Black Coating for Increased Absorbance on Both Sides

P5V

Ø5 µm Pinhole,

Ø1" Housing,
Vacuum Compatible

P100V

Ø100 µm Pinhole,

Ø1" Housing,
Vacuum Compatible

P800V

Ø800 µm Pinhole,

Ø1" Housing,
Vacuum Compatible

P2000V

Ø2 mm Pinhole,

Ø1" Housing,
Vacuum Compatible

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Features

  • Precision Pinholes in Stainless Steel Foils Mounted in Ø1" Vacuum-Compatible Stainless Steel Housings
    • Ø5 µm to Ø2 mm Pinholes Available
  • Black Physical Vapor Deposition (PVD) Coating for Increased Absorbance on Both Sides

Single, mounted, precision pinholes offer small optical apertures for applications such as alignment, beam conditioning, and imaging. The pinholes offered here use 300 series stainless steel foils with a black PVD coating, are mounted in Ø1" vacuum-compatible stainless steel housings, and range in size from Ø5 µm to Ø2 mm. We also offer pinholes with a variety of other foil materials; see the table to the right for options.

For many applications, such as holography, spatial intensity variations in the laser beam are unacceptable. Using precision pinholes in conjunction with positioning and focusing equipment such as our KT311(/M) Spatial Filter System creates a "noise" filter, effectively stripping variations in intensity out of a Gaussian beam. Please see the Tutorial tab for more information on spatial filters.

Precision Pinhole Options
Thorlabs' precision pinholes are available with an assortment of fabrication materials and coatings. The choice of a particular size and material should depend on the application. Low-power applications may benefit more from the absorbance of our blackened stainless steel foils, which are offered in anodized-aluminum housings, or our stainless steel foils with a black PVD coating, which are offered in vacuum-compatible stainless steel housings. High-power applications may need the high damage threshold and reflectance of gold-plated copper foils, the high melting point and lower reflectance of our tungsten foils, or the high melting point of our molybdenum foils paired with the low reflectance (4% @ 800 nm) of their black-coated front side. Please see the Foil Comparison and Graph tabs for more information.

In addition to single pinholes, Thorlabs also offers pinhole wheels that contain 16 radially-spaced pinholes that are lithographically etched onto a chrome-plated fused silica substrate. These wheels allow the user to test multiple pinhole sizes within a setup.

If you do not see what you need among our stock pinhole offerings, it is possible to special order pinholes that are fabricated from different substrate materials, have different pinhole sizes, incorporate multiple holes in one foil, or provide different pinhole configurations. Customized pinhole housings are also available. Please contact Tech Support to discuss your specific needs.

Precision Pinhole and Optical Slit Selection Guide
Material Product
Blackened Stainless Steel Circular Precision Pinholes
Square Precision Pinholes
Optical Slits
Stainless Steel with
PVD Black Coating
Circular Precision Pinholes
Gold-Plated Copper Foil (Rear)
and PVD Black Coating (Front)
Circular Precision Pinholes
Tungsten Foil Circular Precision Pinholes
Molybdenum Foil (Rear) and
Absorptive Polymer Coating (Front)
Circular Precision Pinholes

Precision Pinholes and Slits
Thorlabs offers precision pinholes with blackened stainless steel, gold-plated copper, tungsten, or molybdenum foils. Our pinholes with stainless steel foils are blackened on both sides for increased absorbance and are available from stock in circles from Ø1 µm to Ø9 mm and squares from 100 µm x 100 µm to 1 mm x 1 mm. Our stainless steel pinholes with a black PVD coating are vacuum compatible and available in 5 μm to 2 mm diameters. Our pinholes with gold-plated copper foils, plated with gold on one side and black PVD coated on the reverse, are available with pinhole diameters from 5 µm to 2 mm. Our pinholes with tungsten foils are uncoated and available with pinhole diameters from 5 µm to 2 mm. Lastly, our pinholes with molybdenum foils have an absorptive polymer coating on the front sides and are available with pinhole diameters from 5 µm to 2 mm. We also offer slits in blackened stainless steel foils from stock with slit widths from 5 to 200 µm.

If you do not see what you need among our stock pinhole and slit offerings, it is also possible to special order pinholes and slits that are made with different foil materials, have different hole sizes and shapes, incorporatoles in one foil, or provide different hole configurations. Please contact Tech Support to discuss your specific needs. For more information on the properties of the bulk materials from which the pinholes are fabricated, see the table below.

 

Material Properties
Depending on the application, it can be important to consider the material properties of the pinhole or slit. The material used to construct the aperture can have varying levels of melting point, density, and thermal conductivity, as detailed in the table below.

Material Properties
Material 300 Series Stainless Steela Copperb Tungsten Molybdenumc
Melting Point 1390 - 1450 °C 1085 °C 3422 °C 2623 °C
Density 8.03 g/cm3 8.96 g/cm3 19.25 g/cm3 10.28 g/cm3
Brinell Hardness 170 MPa 878 MPa 2570 MPa 1500 MPa
Damage Thresholdd (10 ns Pulse, 1 kHz @ 355 nm) 1.54 MW/mm2 4.82 MW/mm2 9.39 MW/mm2 6.34 MW/mm2
Thermal Expansion Coefficient 16.2 (µm/m)/°C 16.7 (µm/m)/°C 4.5 (µm/m)/°C 5.0 (µm/m)/°C
Specific Heat @ 20 °C 485 J/(K*kg) 385 J/(K*kg) 134 J/(K*kg) 250 J/(K*kg)
Thermal Conductivity 16.2 W/(m*K) 401 W/(m*K) 173 W/(m*K) 138 W/(m*K)
Thermal Diffusivity @ 300 K 3.1 mm2/s 111 mm2/s 80 mm2/s 54.3 mm2/s
  • Stainless steel pinholes and slits are blackened on both sides to increase absorbance. The material properties will be predominantly that of bulk stainless steel.
  • Gold-plated copper pinholes have a thin coating of gold on one side of the bulk copper foil. With a beam incident on this side, reflectance will be dominated by the properties of the thin gold coating (77% @ 800 nm), while thermal properties will be predominantly copper-based.
  • Molybdenum pinholes have an absorptive coating on the front side. The material properties will be predominantly that of bulk molybdenum.
  • Damage threshold data refers to the bulk materials listed here only.

 

Reflectance
The reflectance of the foil material or coating affects performance in a variety of applications. Below is presented a reflectance graph for all the materials and coatings that are offered with our circular and square precision pinholes, as well as our mounted optical slits. The raw reflectance data can be found here.

It is important to note that the front of the gold-plated copper foil circular precision pinholes have a low-reflectance PVD black coating. The rear of these pinholes leaves the gold-plated copper foil bare. This also occurs on the molybdenum foil circular precision pinholes, which have a low-reflectance absorptive polymer coating on the front and the molybdenum foil is left bare on the back.

Reflectance Graph

Below is presented a reflectance graph for the blackened stainless steel on the circular precision pinholes. The raw reflectance data can be found here.

Principles of Spatial Filters

For many applications, such as holography, spatial intensity variations in the laser beam are unacceptable. Our KT311 spatial filter system is ideal for producing a clean Gaussian beam.

Spatial Filter System Ray Diagram

Figure 1: Spatial Filter System

The input Gaussian beam has spatially varying intensity "noise". When a beam is focused by an aspheric lens, the input beam is transformed into a central Gaussian spot (on the optical axis) and side fringes, which represent the unwanted "noise" (see Figure 2 below). The radial position of the side fringes is proportional to the spatial frequency of the "noise".

Input Gaussian Beam

Figure 2

By centering a pinhole on a central Gaussian spot, the "clean" portion of the beam can pass while the "noise" fringes are blocked (see Figure 3 below).

Clean Gaussian Beam

Figure 3

The diffraction-limited spot size at the 99% contour is given by:

Diffraction-Limited Spot Size

where λ = wavelength, ƒ=focal length and r = input beam radius at the 1/e2 point.

Choosing the Correct Optics and Pinhole for Your Spatial Filter System

The correct optics and pinhole for your application depend on the input wavelength, source beam diameter, and desired exit beam diameter.

For example, suppose that you are using a 650 nm diode laser source that has a diameter (1/e2) of 1.2 mm and want your beam exiting the spatial filter system to be about 4.4 mm in diameter. Based on these parameters, the C560TME-B mounted aspheric lens would be an appropriate choice for the input side of spatial filter system because it is designed for use at 650 nm, and its clear aperture measures 5.1 mm, which is large enough to accommodate the entire diameter of the laser source.

The equation for diffraction limited spot size at the 99% contour is given above, and for this example, λ = (650 x 10-9 m), f = 13.86 mm for the C560TM-B, and r = 0.6 mm. Substitution yields

Spot Size Example

Diffraction-Limited Spot Size (650 nm source, Ø1.2 mm beam)

The pinhole should be chosen so that it is approximately 30% larger than D. If the pinhole is too small, the beam will be clipped, but if it is too large, more than the TEM00 mode will get through the pinhole. Therefore, for this example, the pinhole should ideally be 19.5 microns. Hence, we would recommend the mounted pinhole P20D, which has a pinhole size of 20 μm. Parameters that can be changed to alter the beam waist diameter, and thus the pinhole size required, include changing the input beam diameter and focal length of focusing lens. Decreasing the input beam diameter will increase the beam waist diameter. Using a longer focal length focusing lens will also increase the beam waist diameter.

Finally, we need to choose the optic on the output side of the spatial filter so that the collimated beam's diameter is the desired 4.4 mm. To determine the correct focal length for the lens, consider the following diagram in Figure 4, which is not drawn to scale. From the triangle on the left-hand side, the angle is determined to be approximately 2.48o. Using this same angle for the triangle on the right-hand side, the focal length for the plano-convex lens should be approximately 50 mm.

Spatial Filter Diagram

Figure 4:
 Beam Expansion Example

For this focal length, we recommend the LA1131-B plano-convex lens [with f = 50 mm at the design wavelength (λ = 633 nm), this is still a good approximation for f at the source wavelength (λ = 650 nm)].

Note: The beam expansion equals the focal length of the output side divided by the focal length of the input side.

For optimal performance, a large-diameter aspheric lens can be used in place of a plano-convex lens if the necessary focal length on the output side is 20 mm (see AL2520-A, AL2520-B, AL2520-C). These lenses are 25 mm in diameter and can be held in place using the supplied SM1RR Retaining Ring.

Apertures Selection Guide
Aperture Type Representative Image
(Click to Enlarge)
Description Aperture Sizes Available from Stocka
Single Precision Pinholesa
Circular Pinholes in Stainless Steel Foils Ø1 µm to Ø9 mm
Circular Pinholes in Stainless Steel Foils,
Vacuum Compatible
Ø5 µm to Ø2 mm
Circular Pinholes in Gold-Plated Copper Foils Ø5 µm to Ø2 mm
Circular Pinholes in Tungsten Foils Ø5 µm to Ø2 mm
Circular Pinholes in Molybdenum Foils Ø5 µm to Ø2 mm
Square Pinholes in Stainless Steel Foils 100 to 1000 µm Square
Slitsa Slits in Stainless Steel Foils 3 mm Slit Lengths: 5 to 200 µm Widths
10 mm Slit Lengths: 20 to 200 µm Widths
Annular Apertures Annular Aperture Obstruction Targets on
Quartz Substrates with Chrome Masks
Ø300 µm or Ø2 mm Pinholes with ε Ratiosb of 0.85, 
Ø1 mm Pinholes with ε Ratiosb of 0.05 0.1, or 0.85
Pinhole Wheels Manual, Mounted, Chrome-Plated Fused Silica Disks
with Lithographically Etched Pinholes
Each Disk has 16 Pinholes from Ø25 µm to Ø2 mm and
Four Annular Apertures (Ø100 µm Hole, 50 µm Obstruction)
Motorized Pinhole Wheels with Chrome-Plated Glass Disks
with Lithographically Etched Pinholes
Each Disk has 16 Pinholes from Ø25 µm to Ø2 mm and
Four Annular Apertures (Ø100 µm Hole, 50 µm Obstruction)
  • Single precision pinholes and slits can be special ordered with different aperture sizes, foil materials, shapes, and hole distributions than those offered from stock. Please contact Tech Support with inquiries.
  • Ratio of the Obstruction Diameter to the Pinhole Diameter

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Pinholes, Stainless Steel Foils, Ø1" Housings, Vacuum Compatible

Mounted Pinhole Dimensions
Click to Enlarge

Dimensions for Mounted Stainless Steel Vacuum-Compatible Pinholes in Ø1" Housing
Microscope Image of Pinhole
Click to Enlarge

Microscope Image of Precision Pinhole
  • Precision Pinholes from Ø5 µm to Ø2 mm
  • Stainless Steel Foils have a PVD Black Coating on Both Sides for Increased Absorbance
  • Vacuum-Compatible 300 Series Stainless Steel Housings with 1" Outer Diameters

These mounted precision pinholes are available with pinhole diameters from 5 µm to 2 mm. The foils are fabricated from 300 series stainless steel, plated in a vacuum-chamber with a black PVD coating on both sides, and mounted in Ø1", 0.10" (2.52 mm) thick, vacuum-compatible 300 series stainless steel housings. Each housing is engraved with the pinhole item # and the size of the pinhole.

The foils can be taken out of their housings by removing the retaining ring or spring using small tweezers or pliers; use care as the foil is very thin (50 µm).

Upon request, these pinholes are available with item-specific test reports at an additional cost. Please contact Tech Support for details.

Stainless Steel Pinhole Rear
Click to Enlarge

Rear of Mounted
Vacuum-Compatible Pinhole
Item # Pinhole Diameter Diameter Tolerance Circularity Foil Thickness Foil Material Housing Material Vacuum-Compatibility
P5Va 5 µm ±1 µm >90% 50 µm 300 Series Stainless Steel,
Black PVD Coating
300 Series Stainless Steel 10-9 Torr at 25 °C
with Proper Bake Out;
10-5 Torr at 25 °C
without Bake Out
P10Va 10 µm
P15Va 15 µm ±1.5 µm
P20Va 20 µm ±2 µm
P25Va 25 µm ≥95%
P30Va 30 µm
P40Va 40 µm ±3 µm
P50Va 50 µm
P75Va 75 µm
P100Va 100 µm ±4 µm
P150Va 150 µm ±6 µm
P200Va 200 µm
P300V 300 µm ±8 µm
P400V 400 µm ±10 µm
P500V 500 µm
P600V 600 µm
P700V 700 µm
P800V 800 µm
P900V 900 µm
P1000V 1000 µm
P2000V 2000 µm
  • Includes Engraved Crosshair to Facilitate Alignment
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
P5V Support Documentation
P5VØ1" Mounted Pinhole, 5 ± 1 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$106.07
Today
P10V Support Documentation
P10VØ1" Mounted Pinhole, 10 ± 1 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$106.07
Today
P15V Support Documentation
P15VØ1" Mounted Pinhole, 15 ± 1.5 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$106.07
Today
P20V Support Documentation
P20VØ1" Mounted Pinhole, 20 ± 2 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P25V Support Documentation
P25VØ1" Mounted Pinhole, 25 ± 2 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P30V Support Documentation
P30VØ1" Mounted Pinhole, 30 ± 2 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P40V Support Documentation
P40VØ1" Mounted Pinhole, 40 ± 3 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P50V Support Documentation
P50VØ1" Mounted Pinhole, 50 ± 3 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P75V Support Documentation
P75VØ1" Mounted Pinhole, 75 ± 3 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P100V Support Documentation
P100VØ1" Mounted Pinhole, 100 ± 4 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P150V Support Documentation
P150VØ1" Mounted Pinhole, 150 ± 6 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P200V Support Documentation
P200VØ1" Mounted Pinhole, 200 ± 6 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P300V Support Documentation
P300VØ1" Mounted Pinhole, 300 ± 8 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P400V Support Documentation
P400VØ1" Mounted Pinhole, 400 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P500V Support Documentation
P500VØ1" Mounted Pinhole, 500 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P600V Support Documentation
P600VØ1" Mounted Pinhole, 600 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P700V Support Documentation
P700VØ1" Mounted Pinhole, 700 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P800V Support Documentation
P800VØ1" Mounted Pinhole, 800 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P900V Support Documentation
P900VØ1" Mounted Pinhole, 900 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P1000V Support Documentation
P1000VØ1" Mounted Pinhole, 1000 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today
P2000V Support Documentation
P2000VØ1" Mounted Pinhole, 2000 ± 10 µm Pinhole Diameter, Stainless Steel, Vacuum Compatible
$98.08
Today