Molded Glass Aspheric Lenses: Finite Conjugate, Uncoated


  • High NA (0.10 to 0.65)
  • Diffraction-Limited Design
  • Focus Light with a Single Element
  • Finite Magnification for Focusing From a Point Source

C200TMD

(Not to Scale)

Application Idea

Mounted Aspheric Lens in a Fiber Launch System

354450

355465

355915

Related Items


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Zemax Files
Click on the red Document icon next to the item numbers below to access the Zemax file download. Our entire Zemax Catalog is also available.

Features

  • Molded Glass Aspheric Lenses Designed for Finite Magnification
  • Focus Light Without Introducing Spherical Aberration
  • Available Unmounted or Pre-Mounted in Non-magnetic 303 Stainless Steel Lens Cells
    Engraved with the Item #

Aspheric lenses are designed to focus light without introducing spherical aberration into the transmitted wavefront. For monochromatic sources, spherical aberration is often what prevents a single spherical lens from achieving diffraction-limited performance when focusing light. Thus, an aspheric lens is often the best single element solution for many applications including coupling light into a fiber, spatial filtering, or imaging light onto a detector.

This page features our selection of uncoated, finite conjugate molded glass aspheric lenses. Please note that Thorlabs also offers a large selection of infinite molded aspheric lenses either uncoated or with one of our AR coatings deposited on both sides (see links in the Aspheric Lens Selection Guide table to the right).

Several of these molded glass lenses are available premounted in non-magnetic 303 stainless steel lens cells that are engraved with the mounted part number for easy identification. The mounted versions feature an external M6 x 0.5 metric thread, making it easy to integrate them into an optical setup or OEM application. Mounted aspheres are readily adapted to our SM1 series of lens tubes by using our Aspheric Lens Adapters. They can be used as a drop-in replacement for multi-element microscope objectives by combining the lens with our Microscope Objective Adapter Extension Tube.

Molded glass aspheres are manufactured from a variety of optical glasses to yield the indicated performance. The molding process will cause the properties of the glass (e.g., Abbe number) to deviate slightly from those given by glass manufacturers. Specific material properties for each lens can be found by clicking on the Info Icon () in the tables below and selecting the Glass tab.

Choosing a Lens

Aspheric lenses are commonly chosen to couple incident light into a single mode fiber. The examples below illustrate the key specifications to consider when trying to choose the correct lens.

Example 1: Coupling from a Laser Diode to SM Fiber
Fiber: 780HP, MFD = 5.0 µm at 850 nm
Laser Diode: L850P010

On the emission side, the L850P010 laser diode emits 850 nm laser light at a half-angle FWHM of 5° for the minor axis and 15° for the major axis. This FWHM can be converted to the Gaussian 1/e2 width by multiplying by a factor of 1.7, which can then be used to quantify the numerical aperture (NA),

Numerical Aperture

where θ is the relevant Gaussian half-angle (here given in degrees) and n is the refractive index of the surrounding medium. When used in air (n = 1), this yields an NA of 0.15 and 0.43 for the minor and major axes respectively. To collect as much light as possible, the major axis with the higher numerical aperture of at least 0.43 should be considered when choosing a lens. To avoid edge effects and collect as much light as possible, an NA slighty higher than that calculated can provide better coupling efficiency.

On the collection side, 780HP single mode (SM) fiber has a mode field diameter (MFD) of 5.0 µm at a wavelength of 850 nm. The acceptance (or divergence) angle (θSM) of a single mode fiber in radians, when measured in the far field, is given by the equation below:

Equation for Far Field Divergence Angle in Single Mode Fiber

For 780HP fiber, this yields an acceptance angle of 6.2° and an NA of 0.11, so a lens with an NA greater than 0.11 is needed on the collection side. Note that the NA given on an SM fiber spec sheet should not be used as the acceptance angle for SM fiber, since it does not take wavelength-dependent Gaussian beam propagation factors into account; more details can be found here.

Thorlabs offers a selection of mounted and unmounted aspheric lenses to choose from to meet these NA requirements. One good option would be Item # 355915, which has an NA for the emission side of 0.50 and an NA for the collection side of 0.12.

Example 2: Coupling from a High NA SM Fiber to a More Standard SM Fiber
High NA Fiber: UHNA3, MFD = 4.1 µm at 1550 nm
Standard SM Fiber: SMF-28e+, MFD = 10.4 µm at 1550 nm

To efficiently couple light into the core of a single mode (SM) fiber, the waist of the incident beam should be located at the fiber's end face and the waist diameter should equal the fiber's mode field diameter (MFD); more details can be found here. That means that the magnification of the lens needed to efficiently couple from one fiber to another is given by

Magnification

where the beam waist (w) corresponds to the MFD of each fiber. In this example, this yields a desired magnification of 2.53. Of the available options, Item # 355201 with a magnification of 2.8 is well suited for this coupling.

Aspheric Lens Design Variables
Click to Enlarge

Reference Drawing

Aspheric Lens Design Formula

Definitions of Variables
z Sag (Surface Profile) as a Function of Y
Y Radial Distance from Optical Axis
R Radius of Curvature
k Conic Constant
An nth Order Aspheric Coefficient

The aspheric surfaces of these lenses may be described using a polynomial expansion in Y, the radial distance from the optical axis. The surface profile or sagitta (often abbreviated as sag) is denoted by z, and is given by the following expression:

where R is the radius of curvature, k is the conic constant, and the An are the nth order aspheric coefficients. The sign of R is determined by whether the center of curvature for the lens surface is located to the right or left of the lens' vertex; a positive R indicates that the center of curvature is located to the right of the vertex, while a negative R indicates that the center of curvature is located to the left of the vertex. For example, the radius of curvature for the left surface of a biconvex lens would be specified as positive, while the radius of curvature for its right surface would be specified as negative.

Aspheric Lens Coefficients

Due to the rotational symmetry of the lens surface, only even powers of Y are contained in the polynomial expansion above. The target values of the aspheric coefficients for each product can be found by clicking either on the blue Info Icons in the tables below (info) or on the red documents icon (docs) next to each lens sold below.


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AR Coating Abbreviations
Abbreviation Description
U Uncoated: Optics Do Not have an AR Coating
A Broadband AR Coating for the 350 - 700 nm Range
B Broadband AR Coating for the 600 - 1050 nm or 650 - 1050 nm Range
C Broadband AR Coating for the 1050 - 1620 nm or 1050 - 1700 nm Range
V Narrowband AR Coating Designed for the Wavelength Listed in the Table Below

The tables below contain all molded glass visible and near-IR aspheric lenses offered by Thorlabs. For our selection of IR molded glass aspheres, click here. The Item # listed is that of the unmounted, uncoated lens. An "X" in any of the five AR Coating Columns indicates the lens is available with that coating (note that the V coating availability is indicated with the AR coating wavelength). The table to the right defines each letter and lists the specified AR coating range. Clicking on the X takes you to the landing page where that lens (mounted or unmounted) can be purchased.

Finite Conjugate Aspheric Lenses
Base Item # AR Coating Options Effective
Focal Length
NA Outer Diameter of
Unmounted Lens
Working Distance Clear Aperture of
Unmounted Lens
U A B C V Unmounted Mounted
355104 X 0.3 mm 0.65 1.600 mm S1: 0.1 mma
S2: 1.0 mma
- S1: Ø0.29 mm
S2: Ø0.48 mm
355465 X 0.5 mm S1: 0.50
S2: 0.10
1.845 mm S1: 0.3 mma
S2: 2.9 mma
- S1: Ø0.40 mm
S2: Ø0.70 mm
355585 X 0.6 mm S1: 0.50
S2: 0.10
2.345 mm S1: 0.3 mma
S2: 3.0 mma
- S1: Ø0.35 mm
S2: Ø0.66 mm
355587 X 0.6 mm S1: 0.50
S2: 0.11
1.800 mm S1: 0.3 mma
S2: 2.9 mma
- S1: Ø0.35 mm
S2: Ø0.68 mm
355915 X 0.8 mm S1: 0.50
S2: 0.12
1.300 mm S1: 0.7 mma
S2: 3.9 mma
S1: 0.6 mma,b
S2: 0.8 mma,b
S1: Ø0.77 mm
S2: Ø1.00 mm
355200 X 1.1 mm S1: 0.43
S2: 0.12
2.400 mm S1: 0.5 mmc
S2: 4.8 mma
S1: 0.4 mmb,c
S2: 2.4 mma,b
S1: Ø1.24 mm
S2: Ø1.24 mm
355201 X 1.1 mm S1: 0.12
S2: 0.43
4.929 mm S1: 0.5 mmc
S2: 4.8 mma
S1: 0.2 mmb,c
S2: 2.6 mma,b
S1: Ø1.24 mm
S2: Ø1.24 mm
354450 X 1.2 mm S1: 0.30
S2: 0.30
1.800 mm S1: 1.7 mma
S2: 1.7 mma
- S1: Ø1.14 mm
S2: Ø1.14 mm
355755 X 1.9 mm S1: 0.15
S2: 0.15
1.700 mm S1: 3.6 mma
S2: 3.6 mma
S1: 3.5 mma,b
S2: 0.9 mma,b
S1: Ø1.10 mm
S2: Ø1.10 mm
  • This working distance is measured to the focal point.
  • Measured from the Mount
  • This working distance is measured to the front of the window of the laser diode being collimated.
Infinite Conjugate Aspheric Lenses
Base Item # AR Coating Options Effective
Focal Length
NA Outer Diameter of
Unmounted Lens
Working Distance Clear Aperture of
Unmounted Lens
U A B C V Unmounted Mounted
354710 X X X X 1.5 mm 0.53 2.650 mm 0.5 mma 0.4 mma,b S1: Ø1.15 mm
S2: Ø1.50 mm
354140 X X X X   1.5 mm 0.58 2.400 mm 0.8 mmc 0.8 mmc S1: Ø1.14 mm
S2: Ø1.60 mm
355151 X X X X 2.0 mm 0.50 3.000 mm 0.5 mma 0.3 mma,b S1: Ø1.09 mm
S2: Ø2.00 mm
355440 X X X X 2.8 mm S1: 0.26
S2: 0.52
4.700 mm S1: 2.0 mma
S2: 7.1 mmc
S1: 1.8 mma,b
S2: 7.09 mmc
S1: Ø3.76 mm
S2: Ø4.12 mm
355392 X X X X 2.8 mm 0.60 4.000 mm 1.5 mmc 1.0 mmb,c S1: Ø2.50 mm
S2: Ø3.60 mm
355390 X X X X 2.8 mm 0.55 4.500 mm 2.2 mmc 2.0 mmb,c S1: Ø3.60 mm
S2: Ø3.60 mm
355660 X X X X 3.0 mm 0.52 4.000 mm 1.6 mmc 1.3 mmb,c S1: Ø2.35 mm
S2: Ø3.60 mm
354330 X X X X 3.1 mm 0.70 6.325 mm 1.8 mmc 1.8 mmb,c S1: Ø3.84 mm
S2: Ø5.00 mm
N414 X X X 3.30 mm 0.47 4.50 mm 1.94 mmc 1.83 mmb,c Ø3.52 mm
354340 X X X 4.0 mm 0.64 6.325 mm 1.48 mma 1.2 mma,b S1: Ø3.77 mm
S2: Ø5.10 mm
357610 X X X 4.0 mm 0.62 6.325 mm 1.5 mma 1.1 mma,b S1: Ø3.39 mm
S2: Ø4.80 mm
357775 X X X 405 4.0 mm 0.60 6.325 mm 1.9 mma 1.5 mma,b S1: Ø3.45 mm
S2: Ø4.80 mm
354350 X X X 4.5 mm 0.40 4.700 mm 2.2 mmc 1.6 mmb,c S1: Ø2.05 mm
S2: Ø3.70 mm
355230 X X X X 1064 4.5 mm 0.55 6.325 mm 2.8 mma 2.4 mma,b S1: Ø3.93 mm
S2: Ø5.07 mm
A230 X X X X 4.51 mm 0.55 6.34 mm 2.91 mmc 2.53 mmb,c Ø4.95 mm
354453 X X X X 4.6 mm 0.50 6.000 mm 2.0 mma 0.9 mma,b S1: Ø3.38 mm
S2: Ø4.80 mm
A390 X X 4.60 mm 0.53 6.00 mm 2.70 mmc 1.64 mmb,c Ø4.89 mm
354430 X X X 5.0 mm 0.15 2.000 mm 4.4 mmc 4.0 mmb,c S1: Ø1.40 mm
S2: Ø1.60 mm
354105 X X X X 5.5 mm 0.60 7.200 mm 3.1 mma 2.0 mma,b S1: Ø4.96 mm
S2: Ø6.00 mm
354171 X X X X 6.2 mm 0.30 4.700 mm 3.4 mma 2.8 mma,b S1: Ø2.72 mm
S2: Ø3.70 mm
355110 X X X X 1064 6.2 mm 0.40 7.200 mm 2.7 mma 1.6 mma,b S1: Ø2.93 mm
S2: Ø5.00 mm
A110 X X X X 6.24 mm 0.40 7.20 mm 3.39 mmc 2.39 mmb,c Ø5.00 mm
A375 X X X 7.50 mm 0.30 6.51 mm 5.90 mmc 5.59 mmb,c Ø4.50 mm
354240 X X X X 1064 8.0 mm 0.50 9.950 mm 4.9 mma 3.8 mma,b S1: Ø6.94 mm
S2: Ø8.00 mm
A240 X X X X 8.00 mm 0.50 9.94 mm 5.92 mmc 4.79 mmb,c Ø8.00 mm
354060 X X X X 9.6 mm 0.27 6.325 mm 7.5 mma 7.1 mma,b S1: Ø5.13 mm
S2: Ø5.20 mm
354061 X X X X 11.0 mm 0.24 6.325 mm 8.9 mma 8.5 mma,b S1: Ø4.63 mm
S2: Ø5.20 mm
A220 X X X 11.00 mm 0.26 7.20 mm 7.97 mmc 6.91 mmb,c Ø5.50 mm
354220 X X X X 1064 11.0 mm 0.25 7.200 mm 6.9 mma 5.8 mma,b S1: Ø4.07 mm
S2: Ø5.50 mm
355397 X X X X 11.0 mm 0.30 7.200 mm 9.3 mma 8.2 mma,b S1: Ø6.24 mm
S2: Ø6.68 mm
A397 X X X 11.00 mm 0.30 7.20 mm 9.64 mmc 8.44 mmb,c Ø6.59 mm
354560 X X X X 13.86 mm 0.18 6.325 mm 12.1 mmc 11.7 mmb,c S1: Ø4.54 mm
S2: Ø5.10 mm
A260 X X X 15.29 mm 0.16 6.50 mm 14.09 mmc 13.84 mmb,c Ø5.00 mm
354260 X X X X 15.3 mm 0.16 6.500 mm 12.7 mma 12.4 mma,b S1: Ø4.61 mm
S2: Ø5.00 mm
A280 X X X 18.40 mm 0.15 6.50 mm 17.13 mmc 16.88 mmb,c Ø5.50 mm
354280 X X X X 1064 18.4 mm 0.15 6.500 mm 15.9 mma 15.6 mma,b S1: Ø5.15 mm
S2: Ø5.50 mm
  • This working distance is measured to the front of the window of the laser diode being collimated.
  • Measured from the Mount
  • This working distance is measured to the focal point.
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EFL = 0.x mm

Item #a Info EFLb NA OD WDc CA TC DW LWTd Mc Glass Performance Thread Suggested
Spanner
Wrench
355104 info 0.3 mm 0.65 1.600 mm S1: 0.1 mme
S2: 1.0 mme
S1: Ø0.29 mm
S2: Ø0.48 mm
0.500 mm 1300 nm - 2.7 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
355465 info 0.5 mm S1: 0.50
S2: 0.10
1.845 mm S1: 0.3 mme
S2: 2.9 mme
S1: Ø0.40 mm
S2: Ø0.70 mm
0.782 mm 1310 nm - 2.8 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
355585 info 0.6 mm S1: 0.50
S2: 0.10
2.345 mm S1: 0.3 mme
S2: 3.0 mme
S1: Ø0.35 mm
S2: Ø0.66 mm
0.508 mm 1550 nm - 4.5 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
355587 info 0.6 mm S1: 0.50
S2: 0.11
1.800 mm S1: 0.3 mme
S2: 2.9 mme
S1: Ø0.35 mm
S2: Ø0.68 mm
0.775 mm 1550 nm - 4.6 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
355915 info 0.8 mm S1: 0.50
S2: 0.12
1.300 mm S1: 0.7 mme
S2: 3.9 mme
S1: Ø0.77 mm
S2: Ø1.00 mm
0.600 mm 1550 nm - 0.3 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
C915TMD 6.2 mm S1: 0.6 mme,f
S2: 0.8 mme,f
M6 x 0.5 SPW306
  • Mounted versions are listed second when available.
  • EFL is specified at the design wavelength for the unmounted lens.
  • Specified at the Design Wavelength
  • Lenses with an LWT specification are designed for laser diode collimation; in these cases, the NA, WD, and wavefront are defined based on the presence of a laser window (not included) of the indicated thickness.
  • This working distance is measured to the focal point.
  • Measured from the Mount

EFL = Effective Focal Length
NA = Numerical Aperture
CA = Clear Aperture

WD = Working Distance
DW = Design Wavelength
TC = Center Thickness

OD = Outer Diameter
LWT = Laser Window Thickness
M = Magnification

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
355104 Support Documentation
355104NEW!f = 0.3 mm, NA = 0.65, WD = 0.1/1.0 mm, DW = 1300 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
355465 Support Documentation
355465f = 0.5 mm, NA = 0.50/0.10, WD = 0.3/2.9 mm, DW = 1310 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
355585 Support Documentation
355585NEW!f = 0.6 mm, NA = 0.50/0.10, WD = 0.3/3.0 mm, DW = 1550 nm, Unmounted Aspheric Lens, Uncoated
$93.27
Today
355587 Support Documentation
355587NEW!f = 0.6 mm, NA = 0.50/0.11, WD = 0.3/2.9 mm, DW = 1550 nm, Unmounted Aspheric Lens, Uncoated
$93.27
Today
355915 Support Documentation
355915f = 0.8 mm, NA = 0.50/0.12, WD = 0.7/3.9 mm, DW = 1550 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
C915TMD Support Documentation
C915TMDNEW!f = 0.8 mm, NA = 0.50/0.12, WD = 0.6/0.8 mm, DW = 1550 nm, Mounted Aspheric Lens, Uncoated
$92.87
Today
Back to Top

EFL = 1.x mm

Item #a Info EFLb NA OD WDc CA TC DW LWTd Mc Glass Performance Thread Suggested
Spanner
Wrench
355200 info 1.1 mm S1: 0.43
S2: 0.12
2.400 mm S1: 0.5 mme
S2: 4.8 mmf
S1: Ø1.24 mm
S2: Ø1.24 mm
1.239 mm 1300 nm 0.300 mm 0.3 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
C200TMD 6.2 mm S1: 0.4 mme,g
S2: 2.4 mmf,g
M6 x 0.5 SPW306
355201g info 1.1 mm S1: 0.12
S2: 0.43
4.929 mm S1: 0.5 mme
S2: 4.8 mmf
S1: Ø1.24 mm
S2: Ø1.24 mm 
1.239 mm 1300 nm 0.305 mm 0.3 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
C201TMD 6.2 mm S1: 0.2 mme,g
S2: 2.6 mmf,g
M6 x 0.5 SPW306
354450 info 1.2 mm S1: 0.30
S2: 0.30
1.800 mm S1: 1.7 mmf
S2: 1.7 mmf
S1: Ø1.14 mm
S2: Ø1.14 mm
1.480 mm 980 nm - 1.0 D-ZK3 Focal Shift /
Spot Size Cross Section
- -
355755 info 1.9 mm S1: 0.15
S2: 0.15
1.700 mm S1: 3.6 mmf
S2: 3.6 mmf
S1: Ø1.10 mm
S2: Ø1.10 mm 
1.000 mm 1577 nm - 1.0 D-ZLaF52LA Focal Shift /
Spot Size Cross Section
- -
C755TMD 6.2 mm S1: 3.5 mmf,g
S2: 0.9 mmf,g
M6 x 0.5 SPW306
  • Mounted versions are listed second when available.
  • EFL is specified at the design wavelength for the unmounted lens.
  • Specified at the Design Wavelength
  • Lenses with an LWT specification are designed for laser diode collimation; in these cases, the NA, WD, and wavefront are defined based on the presence of a laser window (not included) of the indicated thickness.
  • This working distance is measured to the front of the window of the laser diode being focused.
  • This working distance is measured to the focal point.
  • Measured from the Mount
  • This lens is housed in a metal ring.

EFL = Effective Focal Length
NA = Numerical Aperture
CA = Clear Aperture

WD = Working Distance
DW = Design Wavelength
TC = Center Thickness

OD = Outer Diameter
LWT = Laser Window Thickness
M = Magnification

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
355200 Support Documentation
355200f = 1.1 mm, NA = 0.43/0.12, WD = 0.5/4.8 mm, DW = 1300 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
C200TMD Support Documentation
C200TMDNEW!f = 1.1 mm, NA = 0.43/0.12, WD = 0.4/2.4 mm, DW = 1300 nm, Mounted Aspheric Lens, Uncoated
$92.87
Today
355201 Support Documentation
355201f = 1.1 mm, NA = 0.12/0.43, WD = 0.5/4.8 mm, DW = 1300 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
C201TMD Support Documentation
C201TMDNEW!f = 1.1 mm, NA = 0.12/0.43, WD = 0.2/2.6 mm, DW = 1300 nm, Mounted Aspheric Lens, Uncoated
$92.87
Today
354450 Support Documentation
354450f = 1.2 mm, NA = 0.30/0.30, WD = 1.7/1.7 mm, DW = 980 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
355755 Support Documentation
355755f = 1.9 mm, NA = 0.15/0.15, WD = 3.6/3.6 mm, DW = 1577 nm, Unmounted Aspheric Lens, Uncoated
$77.97
Today
C755TMD Support Documentation
C755TMDNEW!f = 1.9 mm, NA = 0.15/0.15, WD = 3.5/0.9 mm, DW = 1577 nm, Mounted Aspheric Lens, Uncoated
$92.87
Today