CFS2-532-FC

• Designed for 532 nm operation and optimized for efficient fiber-to-free-space coupling.
• Single-mode fiber pigtailed design using Thorlabs' 460HP fiber.
• FC/PC connector for convenient connection to standard fiber-optic systems.
• 1.97 mm effective focal length (EFL) for compact beam collimation.
• 0.51 lens NA for high numerical aperture and efficient light collection.
• 2.0 mm clear aperture in an extremely compact package.
• Low full-angle beam divergence: approximately 1.75 mrad at 532 nm.
• Output waist diameter: approximately 0.38 mm.
• Broadband AR coating: 350–700 nm with average reflectance Ravg <0.5%.
• Low insertion loss: <0.2 dB.
• High return loss: 55 dB.
• Supplied with 1 m of single-mode fiber.
• Stainless-steel housing provides a compact and robust optical package.
• Compatible with Thorlabs AD4F and AD9F collimator mounting adapters.

The Thorlabs CFS2-532-FC is a compact single-mode pigtailed aspheric fiber collimator designed for applications operating at 532 nm.

The collimator combines a single-mode 460HP optical fiber with an AR-coated aspheric lens that is rigidly mounted inside a stainless-steel housing. The fiber and lens assembly is factory-aligned to produce a collimated free-space beam at the specified 532 nm alignment wavelength.

With an effective focal length of 1.97 mm and a lens numerical aperture of 0.51, the CFS2-532-FC provides a compact solution for converting light between a single-mode fiber and free-space optical beam. At 532 nm, the output beam has a theoretical full-angle divergence of approximately 1.75 mrad, with an output waist diameter of approximately 0.38 mm.

The collimator uses a broadband 350–700 nm AR coating, allowing it to be used at wavelengths within this range. However, the best collimation performance is obtained at the specified 532 nm alignment wavelength; coupling and collimation performance may decrease as the operating wavelength moves away from the design wavelength.

The CFS2-532-FC is supplied with 1 meter of 460HP single-mode fiber and an FC/PC narrow-key connector. The fiber has a mode-field diameter of approximately 3.5 µm at 532 nm, making it suitable for applications requiring efficient coupling to single-mode optical systems.

Its compact 2.0 mm lens characteristic and 4.0 mm housing diameter make the CFS2-532-FC particularly useful where optical space is limited. It can also be integrated into larger optical assemblies using compatible Thorlabs mounting adapters.

Product Type: SM Pigtail Aspheric Collimator
Part Number: CFS2-532-FC
Alignment Wavelength: 532 nm
Fiber Type: 460HP Single-Mode Fiber
Fiber Length: 1 m
Connector Type: FC/PC, Narrow Key
Effective Focal Length (EFL): 1.97 mm
Lens Numerical Aperture (NA): 0.51
Lens Characteristic / Clear Aperture: 2.0 mm
AR Coating Range: 350–700 nm
Average Reflectance: Ravg <0.5%
Output Waist Diameter: 0.38 mm
Waist Distance: 1.92 mm from the front of the collimator housing
Full-Angle Divergence: 1.75 mrad (0.10°)
Mode Field Diameter: 3.5 µm @ 532 nm
Insertion Loss: <0.2 dB
Return Loss: 55 dB
Housing Outer Diameter: 4.0 mm
Fiber Type: Single Mode
Mounting Adapter Compatibility: AD4F, AD9F

The 1.75 mrad divergence is the theoretical full-angle divergence at the 532 nm alignment wavelength. At the same time, the 0.38 mm waist diameter is the theoretical 1/e² beam diameter at one focal length from the lens.

The CFS2-532-FC is suitable for a wide range of fiber-optic and photonics applications, including:

• Single-Mode Fiber Collimation
• Fiber-to-Free-Space Coupling
• Free-Space-to-Fiber Coupling
• 532 nm Laser Systems
• Laser Beam Delivery
• Fiber-Optic Communication Experiments
• Optical Signal Injection
• Laser Beam Alignment
• Optical Measurement Systems
• Spectroscopy
• Interferometry
• Microscopy
• Nonlinear Optics
• Quantum Optics
• Photonics Research
• Scientific and Laboratory Optical Systems

The CFS2-532-FC is particularly useful when a compact 532 nm single-mode fiber interface is required. Its short EFL and high NA allow it to efficiently interface between a single-mode fiber and a free-space optical system while maintaining a low-divergence output beam. Thorlabs also lists the collimator as compatible with the AD4F and AD9F mounting adapters, making it easier to integrate into laboratory optomechanical setups.