Engineered Diffusers® Tutorial


Engineered Diffusers® Tutorial


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Introduction
Engineered Diffusers®* are designed to homogenize input beams to create non-Gaussian intensity distributions. Thorlabs offers Engineered Diffusers that provide top-hat intensity profiles in circular, square, or line distribution patterns; typical diffusers do not offer this advanced level of control over the divergence angle, spatial distribution of the illumination, and intensity profile. Polymer Engineered Diffusers are a cost-effective option and are available with circular, square, and line distribution patterns (see Polymer Diffusers tab for details). These diffusers are meant to be used in low-power applications. UV Fused Silica Engineered Diffusers are available with a circular distribution pattern (see UVFS Diffusers tab for details) and have a high damage threshold, making them ideal for high-power applications. 

Please see the Technology tab for more information on the technology and fabrication of our Engineered Diffusers.

*Engineered Diffusers® is a registered trademark of VIAVI Solutions, Inc.

Engineered Diffuser Surface 2
Click to Enlarge

SEM Picture of Engineered Diffuser for Display Brightness Enhancement
Engineered Diffuser Surface 1
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SEM Picture of Engineered Diffuser for Projection Screens

Engineered Diffuser® Technology
Thorlabs' Engineered Diffusers provide advanced beam shaping that leads to significant performance enhancements for applications as diverse as lithographic systems, outdoor lighting, displays, backlighting, display brightness enhancement, and projection screens.

Homogeneous diffusers made of, for example, ground glass, opal glass, or holographic elements, consist of repeating, uniform surface patterns across the entire clear aperture that provide only limited control over the shape and intensity profile of the illuminated area, causing the incident light to be used inefficiently. In addition, holographic diffusers are usually limited to monochromatic applications using coherent light. On the other hand, Engineered Diffusers consist of differing, individually manipulated microlens units that provide broadband compatibility and excellent control over the light distribution and beam profile.

Each microlens unit that forms the diffuser is individually specified with respect to its surface profile and location in the array. At the same time, to ensure that the diffuser is stable against variations in the input beam's intensity profile and usable in the visible and IR, the distribution of microlenses is randomized according to probability distribution functions chosen to implement the desired beam shaping functions. The microlens distribution also removes zero-order bright spots and diffraction artifacts from the output. In this manner, Engineered Diffusers retain the best properties of both random and deterministic diffusers.

Engineered Diffuser Fabrication
Click to Enlarge

Diagram of Mastering Process

Fabrication
The master microlens array is produced by a laser writing system developed by VIAVI Solutions, Inc. This system exposes a thick layer of photoresist point-by-point in a raster scan mode, as shown to the left. By modulating the intensity of the laser beam as it is scanned, the degree to which the photoresist is exposed can be varied. A deeply textured, engineered surface is the result, as shown above in the two SEM images of the surface topography.

Comparison to Other Diffuser Technologies
Other common diffuser types include prismatic glass integrating bars, ground glass, opal glass, holographic diffusers, and diffractive diffusers. Prismatic glass integrating bars, though sometimes used in high-end systems, are expensive and occupy a great deal of precious space. Ground and opal glass scatter light equally in all directions but with a low degree of control. In addition, efficiency is generally poor with these simple diffusers. Holographic diffusers are an improvement on these technologies and enable limited production of light distribution patterns, but only offer Gaussian-like intensity profiles and circular or elliptical patterns. In terms of general beam shaping capability, diffractive elements can shape an input beam arbitrarily. However, they are confined to narrow diffusion angles, highly sensitive to wavelength, and cannot eliminate zero-order bright spots collinear with the incident beam. In contrast, Engineered Diffusers provide high transmission efficiencies and the ability to control the divergence angle, spatial distribution, and intensity profile of the diffused light.

For more information on Engineered Diffuser technology and performance, please read our Optical Diffusers Catalog Presentation.

Introduction
These Polymer Engineered Diffusers® are designed to create non-Gaussian intensity distributions in circular or square beam profiles that diverge from the plane of incidence. Below, to the left of the page, are the theoretical approximations of the intensity through the center of the diverging beam profile when illuminating the engineered diffusers with a 633 nm collimated beam. To the right are data compiled from independent tests with laser wavelengths of 488 nm, 637 nm, 785 nm, and 1064 nm to demonstrate the change in output profile with wavelength. The highlighted region of each graph denotes the divergence angle of the engineered diffuser. At the bottom of this tab is a description of the laboratory setup and procedure used to collect these data and the results.

Circular Pattern Diffusers Transmitted Intensity Plots

diffuser, tophat transmitted intensity profileClick to Enlarge
Theoretical Data for ED1-C20

diffuser, top hat transmission intensityClick to Enlarge
Experimental Data for ED1-C20
Raw Data
diffuser, transmission, tophat intensity distributionClick to Enlarge
Theoretical Data for ED1-C50

diffuser, top hat transmission intensityClick to Enlarge
Experimental Data for ED1-C50
Raw Data

Square Pattern Diffusers Transmitted Intensity Plots

diffuser, tophat, transmission intensityClick to Enlarge
Theoretical Data for ED1-S20

diffuser, top hat transmission intensityClick to Enlarge
Experimental Data for ED1-S20
Raw Data

diffuser, top hat transmission intensityClick to Enlarge
Theoretical Data for ED1-S50

diffuser, top hat transmission intensityClick to Enlarge
Experimental Data for ED1-S50
Raw Data

Line Pattern Diffuser Transmitted Intensity Plot

diffuser, tophat transmission line profile
Click to Enlarge

Theoretical Data for ED1-L4100

Experimental Set Up
Click to Enlarge
View Imperial Product List
Item #QtyDescription
Sources and Heat Sinks
LP488-SF201488 nm, 20 mW, B Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
LP637-SF701637 nm, 70 mW, G Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
LP785-SF1001785 nm, 100 mW, H Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
DBR1064S11064 nm, 40 mW, Butterfly DBR Laser, SM Fiber, FC/APC, Internal Isolator
LDM9LP1LD/TEC Mount for Thorlabs Fiber-Pigtailed Laser Diodes
LM14S21Universal 14-Pin Butterfly Laser Diode Mount
Collimators and Associated Mounts
TC06FC-5431543 nm, f=5.96 mm, NA=0.28, FC/PC Triplet Collimator
TC06FC-6331633 nm, f=6.01 mm, NA=0.28, FC/PC Triplet Collimator
TC06APC-7801780 nm, f=6.06 mm, NA=0.28, FC/APC Triplet Collimator
TC06APC-106411060 nm, f=6.12 mm, NA=0.28, FC/APC Triplet Collimator
KAD12F1SM1-Threaded Kinematic Pitch/Yaw Adapter for Ø12 mm Cylindrical Components
LMR11Lens Mount with Retaining Ring for Ø1" Optics, 8-32 Tap
TR31Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
PH31Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 3"
R21Slip-On Optical Post Collar for Ø1/2" Posts, 1/4"-20 Thumbscrew
Engineered Diffusers and Associated Mounts
ED1-C201Ø1" Unmounted Polymer Engineered Diffuser, 20° Circle Pattern
ED1-C501Ø1" Unmounted Polymer Engineered Diffuser, 50° Circle Pattern
ED1-S201Ø1" Unmounted Polymer Engineered Diffuser, 20° Square Pattern
ED1-S501Ø1" Unmounted Polymer Engineered Diffuser, 50° Square Pattern
CP331SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, 8-32 Tap
TR31Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
PH21Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 2"
R21Slip-On Optical Post Collar for Ø1/2" Posts, 1/4"-20 Thumbscrew
CR11Continuous 360° Rotation Stage with 8-32, 6-32, and 4-40 Mounting Taps
CR1A1Adapter Plate for CR1 Rotation Stage
Collection Lens and Associated Mounts
LA1304-ML1Ø1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 40 mm, Uncoated
SM05L201SM05 Lens Tube, 2" Thread Depth, One Retaining Ring Included
SM05RC1Slip Ring for SM05 Lens Tubes, 8-32 Tap
TR31Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
PH61Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 6"
Detector and Associated Mounts
SM05PD1A1Large Area Mounted Silicon Photodiode, 350 - 1100 nm, Cathode Grounded
SMR051Ø1/2" Lens Mount with SM05 Internal Threads and No Retaining Lip, 8-32 Tap
SM05D5D1SM05 Ring-Actuated Iris Diaphragm (Ø0.6 - Ø5.0 mm)
TR22Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 2"
MFF1011Motorized Filter Flip Mount with Ø1" Optic Holder, 8-32 Tap
LMR052Lens Mount with Retaining Ring for Ø1/2" Optics, 8-32 Tap
TR31Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
RA902Right-Angle Clamp for Ø1/2" Posts, 3/16" Hex
PH41Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 4"
TR61Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 6"
Stages and General Parts
PBG3648F1UltraLight Breadboard, 36" x 48" x 0.98", 1/4"-20 Taps
MP101Rigid Stand with Platform, 1/4"-20 Taps, Height: 151.4 - 216.4 mm
HDR501Heavy-Duty Rotation Stage with SM2-Threaded Center Hole, Imperial
XT34-500134 mm Construction Rail, L = 500 mm
XT34D2-30630 mm Long XT34 Platform with One 1/4" (M6) Counterbore
XT34C26Double Dovetail Clamp for 34 mm Rails, 30 mm Long
FSR11Storage Reel for Patch Cables with Ø900 µm Jackets
T743-1.01High-Performance Black Masking Tape, 1" x 180' (25 mm x 55 m) Roll
Controllers and Drivers
TED200C1Benchtop Temperature Controller, ±2 A / 12 W
LDC205C1Benchtop LD Current Controller, ±500 mA HV
BSC2011One-Channel Benchtop Stepper Motor Controller
View Metric Product List
Item #QtyDescription
Sources and Heat Sinks
LP488-SF201488 nm, 20 mW, B Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
LP637-SF701637 nm, 70 mW, G Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
LP785-SF1001785 nm, 100 mW, H Pin Code, SM Fiber-Pigtailed Laser Diode, FC/PC
DBR1064S11064 nm, 40 mW, Butterfly DBR Laser, SM Fiber, FC/APC, Internal Isolator
LDM9LP1LD/TEC Mount for Thorlabs Fiber-Pigtailed Laser Diodes
LM14S21Universal 14-Pin Butterfly Laser Diode Mount
Collimators and Associated Mounts
TC06FC-5431543 nm, f=5.96 mm, NA=0.28, FC/PC Triplet Collimator
TC06FC-6331633 nm, f=6.01 mm, NA=0.28, FC/PC Triplet Collimator
TC06APC-7801780 nm, f=6.06 mm, NA=0.28, FC/APC Triplet Collimator
TC06APC-106411060 nm, f=6.12 mm, NA=0.28, FC/APC Triplet Collimator
KAD12F1SM1-Threaded Kinematic Pitch/Yaw Adapter for Ø12 mm Cylindrical Components
LMR1/M1Lens Mount with Retaining Ring for Ø1" Optics, M4 Tap
TR75/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
PH75/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=75 mm
R2/M1Slip-On Optical Post Collar for Ø1/2" Posts, M6 Thumbscrew
Engineered Diffusers and Associated Mounts
ED1-C201Ø1" Unmounted Polymer Engineered Diffuser, 20° Circle Pattern
ED1-C501Ø1" Unmounted Polymer Engineered Diffuser, 50° Circle Pattern
ED1-S201Ø1" Unmounted Polymer Engineered Diffuser, 20° Square Pattern
ED1-S501Ø1" Unmounted Polymer Engineered Diffuser, 50° Square Pattern
CP33/M1SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, M4 Tap
TR75/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
PH50/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=50 mm
CR1/M1Continuous 360° Rotation Stage with M4 and 4-40 Mounting Taps
CR1A/M1Adapter Plate for CR1/M Rotation Stage
R2/M1Slip-On Optical Post Collar for Ø1/2" Posts, M6 Thumbscrew
Collection Lens and Associated Mounts
LA1304-ML1Ø1/2" N-BK7 Plano-Convex Lens, SM05-Threaded Mount, f = 40 mm, Uncoated
SM05L201SM05 Lens Tube, 2" Thread Depth, One Retaining Ring Included
SM05RC/M1Slip Ring for SM05 Lens Tubes, M4 Tap
TR75/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
PH150/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=150 mm
Detector and Associated Mounts
SM05PD1A1Large Area Mounted Silicon Photodiode, 350 - 1100 nm, Cathode Grounded
SMR05/M1Ø1/2" Lens Mount with SM05 Internal Threads and No Retaining Lip, M4 Tap
SM05D5D1SM05 Ring-Actuated Iris Diaphragm (Ø0.6 - Ø5.0 mm)
TR50/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 50 mm
MFF101/M1Motorized Filter Flip Mount with Ø1" Optic Holder, M4 Tap
LMR05/M2Lens Mount with Retaining Ring for Ø1/2" Optics, M4 Tap
TR75/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
RA90/M2Right-Angle Clamp for Ø1/2" Posts, 5 mm Hex
PH100/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=100 mm
TR150/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 150 mm
Stages and General Parts
PBG90120A1UltraLight Breadboard, 900 mm x 1200 mm x 25 mm, M6 Taps
MP10/M1Rigid Stand with Platform, M6 x 1.0 Taps, Height: 151.4 - 216.4 mm
XT34-500134 mm Construction Rail, L = 500 mm
XT34D2-30630 mm Long XT34 Platform with One 1/4" (M6) Counterbore
XT34C26Double Dovetail Clamp for 34 mm Rails, 30 mm Long
T743-1.01High-Performance Black Masking Tape, 1" x 180' (25 mm x 55 m) Roll
FSR11Storage Reel for Patch Cables with Ø900 µm Jackets
HDR501Heavy-Duty Rotation Stage with SM2-Threaded Center Hole, Imperial
Controllers and Drivers
TED200C1Benchtop Temperature Controller, ±2 A / 12 W
LDC205C1Benchtop LD Current Controller, ±500 mA HV
BSC2011One-Channel Benchtop Stepper Motor Controller
Note: A previous-generation NR360Sa Rotation Mount was used in the above experimental set-up. High Performance Black Masking Tape was used to cover metal which might reflect laser light. A MFF101 Motorized Flipper with an empty LMR05 is not being used. 
Light Preparation
Wavelength (nm) 488 637 785 1064
Source LP488-SF20 LP637-SF70 LP785-SF100 DBR1064S
Heat Sink LDM9LP LM14S2
Collimator TC06FC-543 TC06FC-633 TC06APC-780 TC06APC-1064

Procedure
Four wavelengths of light were chosen for study: 488 nm, 637 nm, 785 nm, and 1064 nm. These were prepared using the equipment to the right (a full list of all parts used can be found under the photo of the Experimental Set Up). The optical path was approximately 35 cm above the surface of the breadboard; it began when fiber-coupled light sources were collimated with triplet collimators, using a design wavelength as close to the source wavelength as possible. In free space, the beams were incident upon one of the Polymer Engineered Diffusers. The exiting divergent profile was isolated and focused by an LA1304 plano-convex lens attached to an SM05L20 lens tube. The signal was sampled every 0.5° by a SM05PD1A photodiode. This assembly was mounted on the end of an XT34-500 rail. The opposite end of the rail was mounted to a previous-generation NR360Sa rotation stage centered with the engineered diffuser under test in order to sweep the detector and lens assembly through the center of the profile, as illustrated below, and plot normalized intensity versus output angle. The distance between the diffuser and the detector was approximately 43 cm. The output angle was defined with respect to the original optical axis when the diffuser was not within the path. In order to control for ambient light, a 1 kHz sine wave was used to modulate the drive current applied to the laser diode and the signal was acquired with a lock-in amplifier. A LabVIEW program was written to control the setup and acquire the data.

Experimental Limitations
Only one of each Item # was testedb. Stability may have been compromised by the experiment being performed on a PBG11113c breadboard without any isolation. Only the middle of each diffuse shape was measured, so variances in other areas of the shape are possible, including the corners of the square profiles.

Results
It was found that there was little variance in diffuse beam profile with respect to wavelength across the middle of each beam profile. Above, to the left of the page, are the theoretical estimations of intensity across the width of the resulting beam profile. To the right of the page are data compiled from independent tests with various laser wavelengths to verify the theoretical models.

  • This is a previous generation item. Please see HDR50 for an up-to-date replacement.
  • The ED1-L4100 was not tested.
  • This is a previous generation item. Please see the PBG3648F (PBG90120A) for an up-to-date replacement.
Item # Theoretical Experimental Raw Data
Circular Patterns ED1-C20 Click Here
ED1-C50 Click Here
Square Patterns ED1-S20 Click Here
ED1-S50 Click Here
Line Pattern ED1-L4100 Not Available Not Available

The graph below shows the theoretical and experimental beam profile for our EDG5C20 UV Fused Silica Engineered Diffuser®. The theoretical data is an approximation of the intensity through the center of the diverging beam profile when illuminating the diffuser with a 633 nm collimated beam, and is normalized to the relative intensity at 0°. The experimental intensity data was collected using the scatterometer set-up described below with a 635 nm collimated beam, and is an average over measurements on 20 independent diffusers with each individual measurement normalized to its 0° value. The highlighted region denotes the specified divergence angle of the diffuser, which is defined by the FWHM of the relative intensity at 0°.

Transmitted Intensity of the EDG5C20 Engineered Diffuser
Click to Enlarge

Click Here for Raw Data
The theoretical and experimental beam profile for our EDG5C20 UV Fused Silica Engineered Diffuser. The highlighted region denotes the specified divergence angle.


Click to Enlarge
View Imperial Product List
Item #QtyDescription
Laser Input and Collimation
S1FC6351Fabry-Perot Benchtop Laser Source, 635 nm, 2.5 mW, FC/PC
FG105LCA1Multimode Fiber, 0.22 NA, Low OH, Ø105 µm Core, 400 - 2400 nm
RC12FC-P011Protected Silver Reflective Collimator, 450 nm - 20 µm, RFL = 50.8 mm, FC/PC
KM100T1SM1-Threaded Kinematic Mount for Thin Ø1" Optics
TR43Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 4"
PH43Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 4"
BA11Mounting Base, 1" x 3" x 3/8"
PF20-03-P012Ø2" Protected Silver Mirror
KM2002Kinematic Mirror Mount for Ø2" Optics
BE12Ø1.25" Studded Pedestal Base Adapter, 1/4"-20 Threads
CF1252Clamping Fork for Ø1.25" Pedestal Bases, 1.24" Counterbored Slot, Universal
Spatial Filter Assembly and Associated Optics
KT3111Spatial Filter System (Optics & Pinhole Sold Separately)
N10X-PF110X Nikon Plan Fluorite Imaging Objective, 0.3 NA, 16 mm WD
P100K1Ø1" Mounted Pinhole, 100 ± 4 μm Pinhole Diameter, Stainless Steel
Al2550G-A1Ø25.0 mm Diffraction-Limited N-BK7 Aspheric Lens, f = 50.0 mm, NA = 0.20, AR Coated: 350 - 700 nm
CXY1A130 mm Cage System, XY Translating Lens Mount for Ø1" Optics
ER6-P41Cage Assembly Rod, 6" Long, Ø6 mm, 4 Pack
BLP011Variable Height P-Post
PF175B1Clamping Fork for Ø1.85" Pedestal Bases, 2.12" Counterbored Slot, Universal
Sample Mounting
HDR501Heavy-Duty Rotation Stage with SM2-Threaded Center Hole, Imperial
NR360SP81Adapter Plate for HDR50 Stage, SM1 Threaded, 30 mm Cage Compatible, 1/4"-20 and 8-32 Taps
XRN25DR312" Dovetail Rail, 500 mm Long
MBR61Aluminum Breadboard, Ø6.00" x 0.50", 1/4"-20 Double-Density Taps
EDG5C201Ø1/2" Unmounted UV Fused Silica Engineered Diffuser, 20° Circle Pattern
LMR051Lens Mount with Retaining Ring for Ø1/2" Optics, 8-32 Tap
TR21Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 2"
PH21Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 2"
QRP021360° Manual Rotation Platform with Two Hard Stops
BSC2011One-Channel Benchtop Stepper Motor Controller
Signal Detection
MC2000B1Optical Chopper System with MC1F10HP 10/100 Slot (36°) Chopper Blade, 120 VAC Power Cord
TR62Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 6"
PH22Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 2"
BE1R2Ø1.25" Magnetic Studded Pedestal Base Adapter, 1/4"-20 Threads
P1000K1Ø1" Mounted Pinhole, 1000 ± 10 μm Pinhole Diameter, Stainless Steel
CXY1A130 mm Cage System, XY Translating Lens Mount for Ø1" Optics
SM05PD3A1Mounted Silicon Photodiode, 320 - 1100 nm, Cathode Grounded
SM1A6FW1Adapter with External SM1 Threads and Internal SM05 Threads, Knurled Edge
CP331SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, 8-32 Tap
ER2-P41Cage Assembly Rod, 2" Long, Ø6 mm, 4 Pack
LA1951-A-ML1Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 25.4 mm, ARC: 350-700 nm
TR31Ø1/2" Optical Post, SS, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
PH31Ø1/2" Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L = 3"
XRN25-RC21Rail Carrier for Stages with 2" Dovetails, 8-32 Taps and 1/4" Counterbores
AMP1021Transimpedance Amplifier, 100 kHz Bandwidth, Switchable Gain: 1, 10, or 100 kV/A
View Metric Product List
Item #QtyDescription
Laser Input and Collimation
S1FC6351Fabry-Perot Benchtop Laser Source, 635 nm, 2.5 mW, FC/PC
FG105LCA1Multimode Fiber, 0.22 NA, Low OH, Ø105 µm Core, 400 - 2400 nm
RC12FC-P011Protected Silver Reflective Collimator, 450 nm - 20 µm, RFL = 50.8 mm, FC/PC
KM100T1SM1-Threaded Kinematic Mount for Thin Ø1" Optics
TR100/M3Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 100 mm
PH100/M3Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=100 mm
BA1/M1Mounting Base, 25 mm x 75 mm x 10 mm
PF20-03-P012Ø2" Protected Silver Mirror
KM2002Kinematic Mirror Mount for Ø2" Optics
BE1/M2Ø31.8 mm Studded Pedestal Base Adapter, M6 Threads
CF1252Clamping Fork for Ø1.25" Pedestal Bases, 1.24" Counterbored Slot, Universal
Spatial Filter Assembly and Associated Optics
KT311/M1Spatial Filter System, Metric (Optics & Pinhole Sold Separately)
N10X-PF110X Nikon Plan Fluorite Imaging Objective, 0.3 NA, 16 mm WD
P100K1Ø1" Mounted Pinhole, 100 ± 4 μm Pinhole Diameter, Stainless Steel
Al2550G-A1Ø25.0 mm Diffraction-Limited N-BK7 Aspheric Lens, f = 50.0 mm, NA = 0.20, AR Coated: 350 - 700 nm
CXY1A130 mm Cage System, XY Translating Lens Mount for Ø1" Optics
ER6-P41Cage Assembly Rod, 6" Long, Ø6 mm, 4 Pack
BLP01/M1Variable Height P-Post
PF175B1Clamping Fork for Ø1.85" Pedestal Bases, 2.12" Counterbored Slot, Universal
Sample Mounting
HDR50/M1Heavy-Duty Rotation Stage with SM2-Threaded Center Hole, Metric
NR360SP81Adapter Plate for HDR50 Stage, SM1 Threaded, 30 mm Cage Compatible, 1/4"-20 and 8-32 Taps
XRN25DR312" Dovetail Rail, 500 mm Long
MBR150/M1Aluminum Breadboard, Ø150.0 mm x 12.7 mm, M6 Double-Density Taps
EDG5C201Ø1/2" Unmounted UV Fused Silica Engineered Diffuser, 20° Circle Pattern
LMR05/M1Lens Mount with Retaining Ring for Ø1/2" Optics, M4 Tap
TR50/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 50 mm
PH50/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=50 mm
QRP02/M1360° Manual Rotation Platform with Two Hard Stops, Metric
BSC2011One-Channel Benchtop Stepper Motor Controller
Signal Detection
MC2000B1Optical Chopper System with MC1F10HP 10/100 Slot (36°) Chopper Blade, 120 VAC Power Cord
TR150/M2Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 150 mm
PH50/M2Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=50 mm
BE1R/M2Ø31.8 mm Magnetic Studded Pedestal Base Adapter, M6 Threads
P1000K1Ø1" Mounted Pinhole, 1000 ± 10 μm Pinhole Diameter, Stainless Steel
CXY1A130 mm Cage System, XY Translating Lens Mount for Ø1" Optics
SM05PD3A1Mounted Silicon Photodiode, 320 - 1100 nm, Cathode Grounded
SM1A6FW1Adapter with External SM1 Threads and Internal SM05 Threads, Knurled Edge
CP33/M1SM1-Threaded 30 mm Cage Plate, 0.35" Thick, 2 Retaining Rings, M4 Tap
ER2-P41Cage Assembly Rod, 2" Long, Ø6 mm, 4 Pack
LA1951-A-ML1Ø1" N-BK7 Plano-Convex Lens, SM1-Threaded Mount, f = 25.4 mm, ARC: 350-700 nm
TR75/M1Ø12.7 mm Optical Post, SS, M4 Setscrew, M6 Tap, L = 75 mm
PH75/M1Ø12.7 mm Post Holder, Spring-Loaded Hex-Locking Thumbscrew, L=75 mm
XRN25-RC2/M1Rail Carrier for Stages with 2" Dovetails, M4 x 0.7 Taps and M6 Counterbores
AMP1021Transimpedance Amplifier, 100 kHz Bandwidth, Switchable Gain: 1, 10, or 100 kV/A
A scatterometer was built to measure the scattered light from a UV Fused Silica Engineered Diffuser to characterize the beam profile.

Click to Enlarge
Illustration of the Detector Path through the Beam Profile

Experimental Procedure
A scatterometer was built to measure the scatter pattern of 635 nm laser light from a UV Fused Silica Engineered Diffuser. The experimental set-up is displayed in the photo to the right, and a list of parts can be found below the photo. Please note that a lock-in amplifier was used in the experimental set-up but is not included in the list. The output of an S1FC635 fiber laser was collimated using an RC12FC-P01 collimator, and then a KT311 spatial filter system was used to produce a clean and spatially uniform Gaussian beam. The collimated beam was modulated using an MC2000B optical chopper synced with a lock-in amplifier and was incident upon the diffuser under test. The diffuser was mounted to a QRP02 rotation platform, which was connected to an MBR6 aluminum breadboard and attached directly to the optical table through the central aperture of an HDR50 rotation mount. An XRN25DR3 rail with an attached SM05PD3A photodiode was connected to the rotation mount, allowing the detector to sweep through the center of the diffuser's exiting divergent beam profile, as depicted in the image to the right. The detector was mounted approximately 13.5 cm from the diffuser, and the output angle was defined with respect to the original optical axis when the diffuser was not within the path. The detector was synced with the lock-in amplifier and signal was collected every 0.1° using a LabVIEW program for instrument control and data acquisition. The normalized intensity was plotted as a function of output angle.

Key to this experiment was the use of a spatial filter and lock-in amplifier synced with an optical chopper and photodiode detector. This configuration enabled the detection of low intensity scatter from the diffuser, providing a precise measurement of the beam profile.


Posted Comments:
user  (posted 2021-10-26 00:47:39.78)
hello, can the engineered diffusers be used for MCWHLP1 led source if I buy the collimation adapter SM1U25-A?
soswald  (posted 2021-10-27 04:00:08.0)
Dear customer, thank you for your feedback. The engineered diffusers can be used for the beam of the MCWHLP1. For mounting you'll need a thread adapter from the SM2 threading of SM1U25-A to the SM1 threading of the diffuser mounts, e.g. SM2A6.