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APY002 Pitch & Yaw Stage can be mounted on a 3-axis flexure stage in place of the regular top plate, enabling 5-axis control.

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3-Axis Flexure Stage Mounted Directly to a PY004 High-Load Pitch and Yaw Stage for 5-Axis Control

Common Specificationsa
Travel		4.0 mm (0.16")
Travel Mechanism		Parallel Flexure
Deck Height (Nominal)		62.5 mm (2.46")
Optical Axis Height (Nominal)		75 mm (2.95")
Load Capacity (Max)		1 kg (2.2 lbs)
Thermal Stability		1 µm/°C
Parallelism of Top Plate		<100 µm
Top Plate Mounting Holes	Imperial Plate (Item # MMP1)
	Metric Plate (Item # MMP1/M)

• Please see the Specs Tab for Complete Specifications

Features

• 4 mm of X, Y, and Z Travel
• Flexure Design Ensures Smooth Continuous Motion and Long-Term Stability
• Grooved Top Plate Ensures Alignment of Multi-Axis Stage Accessories
• Compact Size Measuring 112.0 mm x 112.0 mm Without Drives
• All Adjusters Coupled to the Base to Minimize Crosstalk
• Modular Design for Interchanging Actuators

Thorlabs' 3-Axis NanoMax Flexure Stages are ideal for use in fiber launch systems or applications that require sub-micron repeatability. The parallel flexure design ensures precise, smooth, and continuous motions with negligible friction. Each unit provides 4 mm of X, Y , and Z travel with a maximum load capacity of 1 kg. The nominal deck height of the stage is 62.5 mm, which matches that of our 3-Axis MicroBlock compact flexure stages and RollerBlock long travel stages. Adapter plates are available for mounting our NanoMax stages to a wide range of other Thorlabs rotation and long travel linear stages.

Precision Drives
Stages that are pre-configured with differential micrometer actuators or stepper motor actuators are offered below for out-of-the-box operation. The modular design of our 3-axis NanoMax stages allows the drives to be removed and replaced at any time. For compatible drive options, please see the Drives tab. The drives are coupled directly to the base to minimize any unwanted motion in the system. For nanopositioning applications, we have versions with internal piezoelectric actuators.

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HCS013 Objective Mount and HFF001 Quick-Release Fiber Clamp Accessories Attached to the Top Plate Using AM010 Cleats for Fiber Launch Applications

Piezo Options
These stages are available with or without integrated open- or closed-loop piezos. The piezoelectric actuators have 20 µm of travel and can be controlled using many of our open- or closed-loop piezo controllers (see the Specs tab for all compatible controllers). When these stages are coupled with a NanoTrak^® controller (e.g. K-Cubes, benchtop, or rack system module), the system becomes a powerful auto-alignment solution that maintains optical throughput and eliminates coupling efficiency loss due to thermal drift or other external forces. These piezo stages include three PAA100 Drive Cables and, in the case of closed-loop systems, three PAA622 Feedback Converter Cables.

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Piezo and Feedback Connections

Stages with closed-loop piezo actuators have internal strain gauge displacement sensors that provide a feedback voltage signal that is linearly proportional to the displacement of the piezoelectric element. This feedback signal can be used to compensate for the hysteresis, creep, and thermal drift that is inherent in all piezoelectric elements.

Please note that the piezo mechanism uses contact with the micrometer drives in order to move the top platform. If for any reason the stage is operated with the micrometer drives removed, blanking plugs must be fitted before the piezo actuators can function. To order blanking plugs, please contact Tech Support.

Easy Alignment of Accessories
Two central keyways in the top platform allow for rapid system reconfiguration while maintaining accessory alignment (see the image above and to the left). The crossed pattern allows for changing the orientation of the stage for right- and left-handed use. A wide range of accessories is available to mount items such as microscope objectives, collimation packages, wave guides, fiber, and much more. If options are required for off-center mounting of components, the grooved top plate can be replaced with the RB13P1 adapter plate (sold at the bottom of this page), which has an array of 1/4"-20 (M6) and 8-32 (M4) mounting holes.

Multi-Axis Stage Accessories
Fiber Mounts	Fiber Rotators	Waveguide Mounts	Diode Mounts	Fixed Mounts	Kinematic Mounts	Top Plates	Extension Platforms	Fiber Chucks	Slide Holders	Kinematic Platforms	Adapter Plates

Stage Specifications

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Step 2
Unscrew the Knurled Knob and Remove the Actuator

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Step 1
Rotate the Actuator Counterclockwise to Disengage the Actuator from the Platform

Modular Drive Options

All 3-Axis NanoMax system have a modular design that allows the drives to be removed and replaced at any time. This allows for mix-and-match customization of actuators depending on the amount of automation or resolution needed on each axis.

Replacing a drive is simple and can be done in three steps. First, retract the leadscrew of the actuator until it is no longer engaging the moving body of the stage. Then unscrew the knurled knob attaching the existing drive to the stage. Finally, attach the new drive to the stage using the same knurled knob.

The drives compatible with our 3-axis NanoMax stages are summarized below. Some drives have limited travel range when used with the NanoMax 3-axis flexure stages; see the table for more details. For more detailed information on each drive, please see the full presentation for our Stepper Motor Drive, Differential Micrometers and Thumbscrew Drives, or In-line Piezo Actuators.

Item #	DRV004	DRV3	DRV208	DRV120
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Actuator Type	Thumbscrew	Differential Micrometera	Stepper Motorb	Piezoelectric with Feedback
Travel Range	8 mm (0.31")c	Coarse: 8 mm (0.31")c Fine: 300 µm	8 mm (0.31")c	20 µm
Adjustment	500 µm/revolution	Coarse: 500 µm/revolution Fine: 50 µm/revolution	-
Resolution	-	-	200 steps/rev of Leadscrew	5 nmd
Compatible Controllers	-		Benchtop: BSC200 Series Rack Module: MST602	Benchtop: BPC300 Series Rack Mount: MPZ601 K-Cubes: KNA-VIS, KNA-IR, or KPC101

• Included with MAX311D(/M), MAX312D(/M), and MAX313D(/M) Stages
• Included with MAX383(/M) and MAX381(/M) Stages
• Range Limited to 4 mm (0.16") by the NanoMax Stage
• Closed Loop

Insights into Optical Fiber

Scroll down to read about:

• What factors affect the amount of light coupled into a single mode fiber?
• Is the max acceptance angle constant across the core of a multimode fiber?

Click here for more insights into lab practices and equipment.

What factors affect the amount of light coupled into a single mode fiber?

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Figure 2 Conditions which can reduce coupling efficiency into single mode fibers include anything that reduces the similarity of the incident beam to the optical properties of the fiber's guided mode. 

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Figure 1 For maximum coupling efficiency into single mode fibers, the light should be an on-axis Gaussian beam with its waist located at the fiber's end face, and the waist diameter should equal the MFD. 

Adjusting the incident beam's angle, position, and intensity profile can improve the coupling efficiency of light into a single mode optical fiber. Assuming the fiber's end face is planar and perpendicular to the fiber's long axis, coupling efficiency is optimized for beams meeting the following criteria (Figure 1):

• Gaussian intensity profile.
• Normal incidence on the fiber's end face.
• Beam waist in the plane of the end face.
• Beam waist centered on the fiber's core. 
• Diameter of the beam waist equal to the mode field diameter (MFD) of the fiber.  

Deviations from these ideal coupling conditions are illustrated in Figure 2.

These beam properties follow from wave optics analysis of a single mode fiber's guided mode (Kowalevicz).

The Light Source can Limit Coupling Efficiency
Lasers emitting only the lowest-order transverse mode provide beams with near-Gaussian profiles, which can be efficiently coupled into single mode fibers.

The coupling efficiency of light from multimode lasers or broadband light sources into the guided mode of a single mode fiber will be poor, even if the light is focused on the core region of the end face. Most of the light from these sources will leak out of the fiber. 

The poor coupling efficiency is due to only a fraction of the light in these multimode sources matching the characteristics of the single mode fiber's guided mode. By spatially filtering the light from the source, the amount of light that may be coupled into the fiber's core can be estimated. At best, a single mode fiber will accept only the light in the Gaussian beam output by the filter.

The coupling efficiency of light from a multimode source into a fiber's core can be improved if a multimode fiber is used instead of a single mode fiber. 

References
Kowalevicz A and Bucholtz F, "Beam Divergence from an SMF-28 Optical Fiber (NRL/MR/5650--06-8996)." Naval Research Laboratory, 2006.

Date of Last Edit: Jan. 17, 2020

Is the max acceptance angle constant across the core of a multimode fiber?

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Figure 3: Step-index multimode fibers have an index of refraction ( n ) that is constant across the core. Graded-index multimode fibers have an index that varies across the core. Typically the maximum index occurs at the center.

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Figure 5: Graded-index multimode fibers have acceptance angles that vary with radius ( ρ ), since the refractive index of the core varies with radius. The largest acceptance angles typically occur near the center, and the smallest, which approach 0°, occur near the boundary with the cladding (0 < ρ₁ < ρ₂ ). Air is assumed to surround the fiber.

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Figure 4: Step-index multimode fibers accept light incident in the core at angles ≤|θ_max | with good coupling efficiency. The maximum acceptance angle is constant across the core's radius ( ρ ). Air is assumed to surround the fiber.

It depends on the type of fiber. A step-index multimode fiber provides the same maximum acceptance angle at every position across the fiber's core. Graded-index multimode fibers, in contrast, accept rays with the largest range of incident angles only at the core's center. The maximum acceptance angle decreases with distance from the center and approaches 0° near the interface with the cladding.

Step-Index Multimode Fiber
The core of a step-index multimode fiber has a flat-top index profile, which is illustrated on the left side of Figure 3. When light is coupled into the planar end face of the fiber, the maximum acceptance angle (θ_max ) is the same at every location across the core (Figure 4). This is due to the constant value of refractive index across the core, since the acceptance angle depends strongly on the index of the cladding. 

Regardless of whether rays are incident near the center or edge of the core, step-index multimode fibers will accept cones of rays spanning angles ±θ_max with respect to the fiber's axis. 

Graded-Index Multimode Fibers
The core of a typical graded-index multimode fiber, shown on the right side of Figure 3, has a refractive index that is greatest at the center of the core and decreases with radial distance ( ρ ). The equation included below the diagram in Figure 5 shows that the radial dependence of the core's refractive index results in a radial dependence of the maximum acceptance angle and numerical aperture (NA). This equation also assumes a planar end face, normal to the fiber's axis that is surrounded by air.

Cones of rays with angular ranges limited by the core's refractive index profile are illustrated Figure 5. The cone of rays with the largest angular spread (±θ_max ) occurs on the fiber's axis (ρ = 0). The angular spread decreases as the radial distance to the axis increases. 

Step-Index or Graded Index?
A step-index multimode fiber has the potential to collect more light than a graded-index multimode fiber. This is due to the NA being constant across the step-index core, while the NA decreases with radial distance across the graded-index core.

However, the graded-index profile causes all of the guided modes to have similar propagation velocities, which reduces the modal dispersion of the light beam as it travels in the fiber.

For applications that rely on coupling as much light as possible into the multimode fiber and are less sensitive to modal dispersion, a step-index multimode fiber may be the better choice. If the reverse is true, a graded-index multimode fiber should be considered.

References
Keiser G, "Section 2.6." Optical Fiber Communications. McGraw-Hill, 1991.

Date of Last Edit: Jan. 2, 2019

Multi-Axis Stage Selection Guide

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In the above application, a 3-Axis NanoMax flexure stage is aligned in front of a 6-axis stage at the proper 112.5 mm deck height using an AMA554 Height Adapter.

3-Axis Stages
Thorlabs offers three different 3-Axis Stage variations: NanoMax flexure stages, MicroBlock compact flexure stages, and RollerBlock long-travel stages. Each stage features a 62.5 mm nominal deck height. Our NanoMax line of 3-axis stages offers built-in closed- and open-loop piezos as well as modular drive options that include stepper motors, differential drives, or additional piezos. The MicroBlock stages are available with differential micrometer drives or fine thread thumbscrews; these drives are not removable. Finally, our RollerBlock stage drivers can be switched out for any actuator that has a Ø3/8" (9.5 mm) mounting barrel.

4- and 5-Axis Stages
Our 4- and 5-axis stages are ideal for the static positioning of waveguides or complex optical elements with respect to our 3-axis or 6-axis high-performance alignment stages. Thorlabs' 5-axis stages have nominal heights of 62.5 mm or 112.5 mm. The AMA554 Height Adapter can be used to raise the deck height of the 3-axis or 4-axis stages to 112.5 mm for compatibility with our 5-axis MicroBlock or 6-Axis NanoMax Stages.

6-Axis Stages
Thorlabs' 6-Axis NanoMax Nanopositioners are ideal for complex, multi-axis positioning and have a nominal deck height of 112.5 mm. These stages offer a common point of rotation and a patented parallel flexure design that allows all actuators to be coupled directly to the base to minimize any unwanted motion in the system. Built-in closed- and open-loop piezo options are available. A selection of modular drive options allows any axis to be manual or motorized with the option for external piezos. Our units without included actuators are also available in right- or left-handed configurations. To increase the stage height of the 3-axis stages to 112.5 mm, we recommend our AMA554 Height Adapter, shown in the image to the right.

A complete selection and comparison of our multi-axis stages is available below.

3-Axis Stages