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3-Axis MicroBlock™ Compact Flexure Stages![]()
MBT602 Compact Flexure Stage MBT616D Compact Flexure Stage RB13P1 Additional Top Plate for Off-Center and General Optics Mounting ![]() Please Wait Features
Thorlabs' 3-axis MicroBlock™ Compact Flexure Stages are ideal for use in fiber launch systems or applications that require micron resolution. The parallel flexure design yields three orthogonal linear translation degrees of freedom without the severe limitations of stiction and friction that are found in traditional bearing-based stages. The use of nested flexure plates allows this stage to operate indefinitely without the need for any lubricant, which is one of the primary sources of drift within positioning devices. Each unit provides 4 mm (0.16") of X, Y , and Z travel with a maximum load capacity of 1 kg (2.2 lbs). The nominal deck height of the stage is 62.5 mm (2.46"), 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 long-travel linear stages. ![]() Click to Enlarge HCS013 Objective Mount and HFF001 Quick-Release Fiber Clamp Accessories Attached to the Top Plate and AMA009 Bracket Using AMA010 Cleats for Fiber Launch Applications ![]() Click to Enlarge AMA554 Height Adapter can be Used to Raise the Deck Height to 112.5 mm, Matching Our 6-Axis NanoMax Stages Precision Drives Easy Alignment of Accessories The crossed pattern allows for changing the orientation of the stage for right- or 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. The MBT616D stage is also available preconfigured with a variety of fiber launch optomechanics.
Insights into Optical FiberScroll down to read about:
Click here for more insights into lab practices and equipment.
When does NA provide a good estimate of the fiber's acceptance angle?![]() Click to Enlarge Figure 1: Rays incident at angles ≤θmax will be captured by the cores of multimode fiber, since these rays experience total internal reflection at the interface between core and cladding. ![]() Click to Enlarge Figure 2: The behavior of the ray at the boundary between the core and cladding, which depends on their refractive indices, determines whether the ray incident on the end face is coupled into the core. The equation for NA can be found using geometry and the two equations noted at the top of this figure. Numerical aperture (NA) provides a good estimate of the maximum acceptance angle for most multimode fibers, as shown in Figure 1. This relationship should not be used for single mode fibers. NA and Acceptance Angle Rays with an angle of incidence ≤θmax are totally internally reflected (TIR) at the boundary between the fiber's core and cladding. As these rays propagate down the fiber, they remain trapped in the core. Rays with angles of incidence larger than θmax refract at the interface between core and cladding, and this light is eventually lost from the fiber. Geometry Defines the Relationship The equations at the top of Figure 2 are expressions of Snell's law and describe the rays' behavior at both interfaces. Note that the simplification sin(90°) = 1 has been used. Only the indices of the core and cladding limit the value of θmax . Angles of Incidence and Fiber Modes Single Mode Fibers are Different Single mode fibers have only one guided mode, the lowest order mode, which is excited by rays with 0° angles of incidence. However, calculating the NA results in a nonzero value. The ray model also does not accurately predict the divergence angles of the light beams successfully coupled into and emitted from single mode fibers. The beam divergence occurs due to diffraction effects, which are not taken into account by the ray model but can be described using the wave optics model. The Gaussian beam propagation model can be used to calculate beam divergence with high accuracy. Date of Last Edit: Jan. 20, 2020
Why is MFD an important coupling parameter for single mode fibers?![]() Click to Enlarge Figure 3 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. The beam output by the fiber also resembles a Gaussian with these characteristics. In the case of single mode fibers, the ray optics model and NA are inadequate for determining coupling conditions. The mode intensity (I ) profile across the radius ( ρ ) is illustrated. As light propagates down a single mode fiber, the beam maintains a cross sectional profile that is nearly Gaussian in shape. The mode field diameter (MFD) describes the width of this intensity profile. The better an incident beam matches this intensity profile, the larger the fraction of light coupled into the fiber. An incident Gaussian beam with a beam waist equal to the MFD can achieve particularly high coupling efficiency. Using the MFD as the beam waist in the Gaussian beam propagation model can provide highly accurate incident beam parameters, as well as the output beam's divergence. Determining Coupling Requirements Single mode fibers have one guided mode, and wave optics analysis reveals the mode to be described by a Bessel function. The amplitude profiles of Gaussian and Bessel functions closely resemble one another, which is convenient since using a Gaussian function as a substitute simplifies the modeling the fiber's mode while providing accurate results (Kowalevicz). Figure 3 illustrates the single mode fiber's mode intensity cross section, which the incident light must match in order to couple into the guided mode. The intensity (I ) profile is a near-Gaussian function of radial distance ( ρ ). The MFD, which is constant along the fiber's length, is the width measured at an intensity equal to the product of e-2 and the peak intensity. The MFD encloses ~86% of the beam's power. Since lasers emitting only the lowest-order transverse mode provide Gaussian beams, this laser light can be efficiently coupled into single mode fibers. Coupling Light into the Single Mode Fiber The coupling efficiency will be reduced if the beam waist is a different diameter than the MFD, the cross-sectional profile of the beam is distorted or shifted with respect to the modal spot at the end face, and / or if the light is not directed along the fiber's axis. References Date of Last Edit: Feb. 28, 2020
Why is MFD an important coupling parameter for single mode fibers?Significant error can result when the numerical aperture (NA) is used to estimate the cone of light emitted from, or that can be coupled into, a single mode fiber. A better estimate is obtained using the Gaussian beam propagation model to calculate the divergence angle. This model allows the divergence angle to be calculated for whatever beam spot size best suits the application. Since the mode field diameter (MFD) specified for single mode optical fibers encloses ~86% of the beam power, this definition of spot size is often appropriate when collimating light from and focusing light into a single mode fiber. In this case, to a first approximation and when measured in the far field,
is the divergence or acceptance angle (θSM ), in radians. This is half the full angular extent of the beam, it is wavelength
Gaussian Beam Approach Instead, this light resembles and can be modeled as a single Gaussian beam. The emitted light propagates similarly to a Gaussian beam since the guided fiber mode that carried the light has near-Gaussian characteristics. The divergence angle of a Gaussian beam can differ substantially from the angle calculated by assuming the light behaves as rays. Using the ray model, the divergence angle would equal sin-1(NA). However, the relationship between NA and divergence angle is only valid for highly multimode fibers. Figure 4 illustrates that using the NA to estimate the divergence angle can result in significant error. In this case, the divergence angle was needed for a point on the circle enclosing 86% of the beam's optical power. The intensity of a point on this circle is a factor of 1/e2 lower than the peak intensity. The equations to the right of the plot in Figure 4 were used to accurately model the divergence of the beam emitted from the single mode fiber's end face. The values used to complete the calculations, including the fiber's MFD, NA, and operating wavelength are given in the figure's caption. This rate of beam divergence assumes a beam size defined by the 1/e2 radius, is nonlinear for distances z < zR, and is approximately linear in the far field (z >> zR). The angles noted on the plot were calculated from each curve's respective slope. When the far field approximation given by Equation (1) is used, the calculated divergence angle is 0.098 radians (5.61°). References Date of Last Edit: Feb. 28, 2020
Multi-Axis Stage Selection Guide![]() Click to Enlarge 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 4- and 5-Axis Stages 6-Axis Stages A complete selection and comparison of our multi-axis stages is available below.
3-Axis Stages
4-Axis Stages
5-Axis Stages
6-Axis Stages
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Thorlabs' MicroBlock compact flexure stage with thumbscrew drives provides 4 mm (0.16") of coarse travel with 500 μm adjustment per revolution. This resolution and travel range make these stages ideal for optimizing the coupling efficiency in a fiber alignment or waveguide positioning system. Please note that unlike our selection of NanoMax™ and RollerBlock™ stages, we do not recommend removing the drives from the stage. Imperial stages come with an MMP1 Top Plate, while metric stages come with an MMP1/M Top Plate. These mounting plates contain a central keyway that allows for easy and repeatable alignment of all of the accessories listed in the overview. If off-center or breadboard mounting is necessary, we also offer the RB13P1 Top Plate. More information on the MMP1(/M) and RB13P1(/M) Top Plates is available below. This stage is also available preconfigured with a variety of fiber launch optomechanics for use in fiber launch systems. ![]()
Thorlabs' MicroBlock compact flexure stage with differential micrometers provides 4 mm (0.16") of coarse travel with 500 µm adjustment per revolution, as well as 300 µm of fine travel with 50 µm travel per revolution. The travel range and resolution make these stages ideal for optimizing the coupling efficiency in a fiber alignment or waveguide positioning system. The graduations also allow for a clear reference point for absolute positioning within a system. Please note that unlike our selection of NanoMax™ and RollerBlock™ stages, we do not recommend removing the drives from the stage. Imperial stages come with an MMP1 Top Plate, while metric stages come with an MMP1/M Top Plate. These mounting plates contain a central keyway that allows for easy and repeatable alignment of all of the accessories listed in the overview. If off-center or breadboard mounting is necessary, we also offer the RB13P1 Top Plate. More information on the MMP1(/M) and RB13P1(/M) Top Plates is available below. This stage is also available preconfigured with a variety of fiber launch optomechanics for use in fiber launch systems. ![]() ![]() Click to Enlarge RB13P1 Top Plate Shown Replacing the MMP1 Crossed Groove Mounting Plate on an MAX311D Flexure Stage
The RB13P1(/M) Adapter Plate is designed as a replacement option for the standard MMP1(/M) grooved top plate sold with the stages above. Four counterbores that accept M3 screws allow it to be attached to the above stages. The 2.36" x 2.36" mounting surface is the same as the MMP1(/M) top plate that is included with the above stages. For complete details on the dimensions and tap locations of this top plate, please see the mechanical drawings below. The MMP1(/M) Top Plate is included with the stages sold above but can be purchased separately as well. This plate features two 3 mm wide central keyways in a crossed pattern to allow for rapid configuration while maintaining accessory alignment, making this plate ideal for fiber launch applications. This "crossed groove" design allows for the NanoMax stages to be used in a left- or right-handed configuration. The plate also contains an array of 4-40 (M2), 6-32 (M3), and 8-32 (M4) tapped mounting holes for securing and mounting various components. For complete details on the dimensions and tap locations of this plate, please see the mechanical drawings. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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