Single-Mode Tapered Lens Fibers
Nanonics provides unique Lens fiber probes for variety of near-field and far-field optical protocols in imaging and nanomanipulation. Such lens fibers have superior capabilities as can be seen in the specs list below.
Accurate tests of lens profiles can be performed, providing detailed optical properties of the lens. These tests are performed using simultaneous near-field/far- field optical techniques and AFM topographical imaging. Our unique and highly accurate testing techniques make the Nanonics Optical Test and Measurement system a benchmark in the photonics industry
Single-Mode fibers from 488 nm up to 1550 nm
Working Distance: 5-50 microns
Numerical apertures up to >0.5
Spot size at the focus: 0.5-7.5 microns
Specific customer requests can be accommodated
Above is an NSOM image in the focal plane of a lensed fiber along with a cross section depicting the light strength at the focus. Note that the spot size is less than 2 microns in diameter.
Table of Lens & Other Standard* Lensing and Cleaving Capabilities
Tapered, bent lensed fiber.
r = Radius of Curvature. α = Angle of Fiber Bend.
|
Parameter
|
Specification (Single-Mode)
|
Specification (Multi- Mode)
|
|
Core Diameter
|
wavelength-dependent
|
50 µm
|
|
Spot Size of Aspheric and Convex Lenses (1/e2)
|
|
|
|
Minimum
|
1.7 µm (λ=1.5 µm)
0.6 µm (λ=0.5 µm)
|
9.0 µm
|
|
Maximum
|
6.0 µm (λ=1.5 µm)
|
30.0 µm
|
|
Spot Size Tolerance
|
|
|
|
Without near-field optical characterization
|
±0.5 µm
|
±0.5 µm
|
|
With near-field optical characterization
|
±0.25 µm
|
±0.25 µm
|
|
Lens Radius of Curvature
|
5-50 µm
|
5-50 µm
|
|
Taper Angle
|
45°-90°
|
45°-90°
|
|
Tolerance of Taper Angle
|
±1°
|
±1°
|
|
Concentricity of Spot Relative to Taper
|
|
|
|
Without near-field optical characterization
|
±0.5 µm
|
±0.5 µm
|
|
With near-field optical characterization
|
±0.25 µm
|
±0.25 µm
|
|
Working Distance
|
|
|
|
Minimum
|
5 µm (λ=1.5 µm)
|
20 µm
|
|
Maximum
|
50 µm (λ=1.5 µm)
|
60 µm
|
|
Numerical Aperture (N.A.)
|
|
|
|
Minimum
|
0.17
|
0.08
|
|
Maximum
|
0.6
|
0.5
|
|
Depth of Focus
|
±1 µm
|
±1 µm
|
|
Minimum Strip Distance
|
2 mm ± 0.1 mm
|
2 mm ± 0.1 mm
|
|
Maximum Strip Distance
|
No limitation
|
No limitation
|
|
Coating Materials
|
|
|
|
Chemical
|
Ni
|
Ni
|
|
Electrochemical
|
Au
|
Au
|
|
Vacuum
|
Cr + Au
|
Cr + Au
|
|
Coating Dimensions
|
|
|
|
Thickness
|
1.0-1.5 µm
|
1.0-1.5 µm
|
|
Minimum Length
|
0.5 mm
|
0.5 mm
|
|
Maximum Length
|
5 cm
|
5 cm
|
|
Positioning Accuracy of Coating Relative to Lens
|
0.5 mm
|
0.5 mm
|
|
Other Lens Geometries:
|
|
|
|
Cylindrical Lens
|
|
|
|
Maximum Major/Minor Axis Ratio
|
4:1
|
N/A
|
|
Ball Lens
|
|
|
|
Maximum Diameter
|
150 µm, for 125 µm cladding
|
N/A
|
|
Fiber Cleaving
|
0°-45°, < ±0.5°
|
0°-45°, < ±0.5°
|
|
Polarization properties of integral lenses on polarization maintaining fibers
|
milli-dB
|
N/A
|
|
Coupling efficiencies
|
|
|
|
With anti-reflection
|
>80%
|
>80%
|
|
Without anti-reflection
|
>70%
|
>70%
|
|
Fiber Assemblies
|
|
|
|
With other fibers
|
maximum separation: >100µm
|
maximum separation: >100µm
|
|
Light concentrating connectors
|
N/A
|
10-50µm
50µm- 1mm
|
|
Fiber Bending Properties
|
|
|
|
Radius of Curvature
|
0.5-2 mm
|
0.5-2 mm
|
|
Angle of Fiber Bend
|
≤80°
|
≤80°
|
|
* Other, non-standard specifications available upon customer request
|
|
