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Plano-Convex Lens, N-BK7, 6.35 mm Diameter, 6.4 mm EFL, 1000-1550 nm
$51

Specifications

  • Lens Shape
    Plano-Convex
  • Lens Material
    N-BK7
  • Antireflection Coating
    1000-1550 nm
  • Coating Type
    IR Multilayer
  • Coating Code
    AR.18
  • Damage Threshold
    7.5 J/cm2, 10 ns pulses, 20 Hz at 1064 nm
  • Surface Quality
    40-20 scratch-dig
  • Surface Accuracy, Irregularity
    λ/4
  • Surface Accuracy, Power
    1.5 λ
  • Chamfers
    0–0.8 mm face width
  • Chamfers Angle/Tolerance
    45° ±15°, typical
  • Focal Length Tolerance
    ±1 %
  • Diameter Tolerance
    +0/-0.1 mm
  • Clear Aperture
    ≥central 90% of diameter
  • Cleaning

Features

N-BK7 Substrates for VIS and NIR Applications

N-BK7 is an excellent lens material for most visible and near infrared applications. It is the most common borosilicate crown optical glass, and it provides great performance at a good value. Its high homogeneity, low bubble and inclusion content, and straightforward manufacturability make it a good choice for transmissive optics. N-BK7 is also relatively hard and shows good scratch resistance. The transmission range for BK 7 is 380 to 2100 nm. It is not recommended for temperature sensitive applications, such as precision mirrors. For more information, refer to our optical materials technical note.

High Quality Precision Plano-Convex Lens Surfaces

Our precision plano-convex lenses are polished to tight tolerances minimizing wavefront distortion. Tight surface quality tolerances minimize scatter and unwanted diffraction effects. These lenses have a 40-20 scratch-dig surface quality, and a 1.5 λ surface power accuracy. For more information, refer to the optical surfaces technical note.

Broadband Multilayer IR Antireflection Coating

Our broadband AR.18 antireflection coating improves the transmission efficiency of these lenses by reducing surface reflections over a 1000-1550 nm wavelength range. The IR AR multi-layer coating improves the performance over uncoated surfaces. It features a damage threshold of 7.5 J/cm‌2 for 10 ns pulses at 20 Hz and 1064 nm.

Standardized Plano-Convex Focal Lengths

Standard effective focal lengths across a variety of newport lens sizes, materials and shapes provide a systematic approach allowing for lenses of different sizes to be interchanged without requiring other changes to your optical system. Collimating a point light source coming from the planar surface or focusing a collimated light source which is incident on the curved surface will help to minimize the spherical aberration.

Plano-Convex Lens Shape for Focusing Light

Plano-Convex lenses are the best choice for focusing parallel rays of light to a single point. They can be used to focus, collect and collimate light. The asymmetry of this lens shape minimizes spherical aberration in situations where the object and image are located at unequal distance from the lens. The optimum case is where the object is placed at infinity with parallel rays entering lens and the final image is a focused point.

Focusing a Collimated Laser Beam

For an application example, let’s look at the case of the output from a Newport R-31005 HeNe laser focused to a spot using a KPX043 Plano-Convex Lens. This Hene laser has a beam diameter of 0.63 mm and a divergence of 1.3 mrad. Note that these are beam diameter and full divergence, so in the notation of our figure, y1 = 0.315 mm and θ1 = 0.65 mrad. The KPX043 lens has a focal length of 25.4 mm. Thus, at the focused spot, we have a radius θ1f = 16.5 µm. So, the diameter of the spot will be 33 µm.

Collimating Light from a Point Source

Since a common application is the collimation of the output from an Optical Fiber, let’s use that for our numerical example. The Newport F-MBB fiber has a core diameter of 200 µm and a numerical aperture (NA) of 0.37. The radius y1 of our source is then 100 µm. NA is defined in terms of the half-angle accepted by the fiber, so θ1 = 0.37. If we again use the KPX043 , 25.4 mm focal length lens to collimate the output, we will have a beam with a radius of 9.4 mm and a half-angle divergence of 4 mrad.

Mounted Version - with Lens Tubes

The lenses can be mounted in LT series lens tube for constructing a complex optical system or quickly connecting to other threaded lens mounts: A-Line™ series fixed lens mount, or adjustable lens positioner (with thread adapter). Use LT-WR series spanner wrench for easy lens installation.

We offer a full range of optical lens mounts to meet various experimental requirements. Below lists the recommended mounts for spherical lenses of standard sizes. Please see our Lens Mount Guide for additional information.

Note: besides the diameter, please check the Edge Thickness (Te) specification of the lens and the lens mount to ensure compatibility before purchasing. 

Lens Diameter LH-A-GRP
A-Line™ Lens Mounts
LT_Series_group_update
LT Series Lens Tubes
OM-multi_axis_lens_pos-S
LP Series Lens Positioners
optics-cage-plus-S
Optics Cage Plus Series
76.2 mm (M-) LH-3A N/A N/A N/A
50.8 mm (M-) LH-2A
LH-2N
LT20-05
LT20-10
LT20-20
LT20-30
LP-2A
LP-2A-XY
LP-2A-XYZ
N/A
38.1 mm (M-) LH-1.5A LT20 lens tube with
LH-2R1.5 adapter
LP-2 lens positioner with
LPLH-1.5T adapter
N/A
25.4 mm (M-) LH-1A
LH-1N
LH-1XY
LH-1TZ-A
LH-1TZ
LT10-05
LT10-10
LT10-20
LT10-30
LP-1A
LP-1A-XY
LP-1A-XYZ
OC1-LH1-S
OC1-LH1
OC1-LH1-TZ
OC1-LH1-XY
OC1-LH1-XYA
OC1-LH1-XYC
OC1-LH1-XYZ
12.7 mm (M-) LH-0.5A
LH-05N
LT05-05
LT05-10
LP-05A
LP-05A-XY
LP-05A-XYZ
N/A
6.35 mm LH-05DB with
LH-50R25 adapter
LT05 lens tube with
LH-50R25 adapter
LP-05 lens positioner with
LPLH-25T adapter
N/A

For non-standard sizes not listed above, check out our variable size lens mounts.