Optical assemblies for coupling into Mid-IR hollow fibers

Optical assemblies are customizable including focal length, lens coating and adapter. Email us with your request or use our online form here.

Direct Mount to Daylight Solutions Laser

Mount attaches to the laser head of CW/Pulsed, HedgeHog, Unicorn, and Uber-Tuner models.

Optical Assemblies for QCL Coupling into Hollow Fiber

Part# CP12MW75-SMA-DL

AR coating for λ = 3 – 5 µm; f = 75 mm; SMA connector; Mount for direct attachment to Daylight Solution CW/Pulsed laser head

Price/ea: $1275

Part# CP12MWLW50-SMA-DL

AR coating for λ = 3 – 12 µm; f = 50 mm; SMA connector; Mount for direct attachment to Daylight Solutions CW/Pulsed laser head

Price/ea: $1475

Part# CP12LW40-SMA-DL

AR coating for λ = 8 – 12 µm; f = 40 mm; SMA connector; Mount for direct attachment to Daylight Solutions CW/Pulsed laser head

Price/ea: $1275

Free-Space (bench-top) Mounting

Coupling optics can be mounted to an optical bench (i.e., free-space) with either metric (M4) or imperial (#8-32) threads for attaching to a post.

Optical Assembly for mid-IR hollow fiber coupling

Part# CP12MW75-SMA-FS

AR coating for λ = 3 – 5 µm; f = 75 mm; SMA connector; Free space mounting; Metric or imperial threads

Price/ea: $1075

Part# CP12MWLW50-SMA-FS

AR coating for λ = 3 – 12 µm; f = 50 mm; SMA connector; Free space mounting; Metric or imperial threads

Price/ea: $1275

Part# CP12LW40-SMA-FS

AR coating for λ = 8 – 12 µm; f = 40 mm; SMA connector; Free space mounting; Metric or imperial threads

Price/ea: $1075

Optical assemblies are customizable including focal length, lens coating and adapter. Email us with your request or use our online form here.

AR Coating

Guiding Photonics selects lens materials and AR coatings for three different wavelength ranges. Note: these ranges are related to, but not identical to the designation of the fiber internal dielectric coatings. In cases where the back reflections from even AR coated lenses pose a concern, we also offer optical assemblies that utilize off-axis-parabolic (OAP) mirrors; however, these assemblies are more difficult to align.

transmission_ar_coating

Focal length

In general, coupling light into hollow core fibers is relatively simple, given the relatively large core. However, both transmission and beam quality can be adversely affected if the proper focal length optic is not used. In general, the beam should enter straight into the fiber with a relatively gradual focus. Optimal coupling into the lowest order mode occurs when the ratio of the focused spot size to the fiber ID, 2ωo / (ID) = 0.64.

focal_length_chart
focused_beam_waist

The calculation for optimal focus assumes an ideal collimated Gaussian input beam, a non-ideal beam will have a larger focused spot. For this reason, we recommend selecting a focal length that is either equal to or less than the optimal focal length. Example recommendations are provided in the table for the case where the input laser beam has a diameter (D = 4 mm) and the fiber internal diameter is (ID = 300 µm).

Wavelength: µm

Laserbeam Diameter: mm

Fiber ID: µm

Optimal Focal Length: mm

table_focal_beam_waist

[1] Rick K. Nubling, James A. Harrington, “Launch conditions and mode coupling in hollow-glass waveguides,” Optical Engineering 37(9), (1998). http://dx.doi.org/10.1117/1.601768

Optical assemblies are customizable including focal length, lens coating and adapter. Email us with your request or use our online form here.

Connector Options

Optical assemblies are available with mating connectors for either SMA or FC terminated fiber cables.

Mounting Options

Coupling optics can be mounted to an optical bench (i.e., free-space) or directly to a Daylight Solutions laser head. Free-space (FS) versions are available with either metric (M4) or imperial (#8-32) threads for attaching to a post. Our standard Daylight (DL) mount attaches to the laser head of CW/Pulsed, HedgeHog, Unicorn, and Uber-Tuner models and can also be used on Mode Hop-Free models with an adapter. A different version (DMC) is available for direct mounting to the Daylight MIRcat laser, although this requires manufacturer modifications to the MIRcat housing. If there are any questions, please provide your specific laser model #, and we will let you know which mount is appropriate.

Optical Assemblies for QCL Coupling into Hollow Fiber
Optical Assembly for mid-IR hollow fiber coupling
mid_ir_fiber_bench_mount

OAP Assemblies

For highly broadband applications, as well as those in which back reflections from an AR coated lens are a concern, we offer optical assemblies that utilize off-axis-parabolic (OAP) mirrors instead of lenses. Note: OAP assemblies are more difficult to align than lens assemblies. If an OAP is required, please inquire about available options.

mid_ir_oap_fiber
qcl_oap_fiber

Collimation/Focusing Assemblies

Guiding Photonics can design custom optics that are optimized for the low-divergence output beam exiting a hollow fiber. This includes simple single lens designs for collimation, as well as, complex high-NA, multi-element designs for focusing to a diffraction limited spot.

3lens focuser coupling assembly for hollow core fiber
Collimating optics for hollow core fiber
Guiding Photonics

Guiding Photonics