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Injection Molded Plastic Aspheric Lenses

pdf.gif (231 bytes) PLASTIC.PDF  (67K) Click on the file name to download an Adobe PDF file covering this section.

Collimating and Focusing Lenses for Laser Diodes

While glass lenses are preferred for their superior optical characteristics (beam quality), there are many product applications where a high quality plastic lens can be effectively utilized. The 300 Series plastic aspheric collimating and objective lenses offer a lower cost alternative to glass and still perform well over a temperature range actually exceeding the upper limit for most laser diodes. Plastic lenses are used in products such as DVD players, laser pointers, construction levels, and less critical alignment and position sensing devices.

< Optima plastic asphere 300-0340-780 shown

If you need a collimated beam with smaller dimensions, consider using the 300-0380-780 lens or, the Laser Diode Mounting Kit P/N LDM 4500 KIT.  For example... when used with the Hitachi HL6312G (635nm/5mW) laser diode, a collimated beam measures approximately 0.715 mm in the parallel axis by 2.85 mm in the perpendicular axis, with divergence angles of 1.2 mrad x 0.34 mrad respectively. (The figures mentioned may vary from one diode to another or, with other manufacturers diodes).

The 300-0380-780 plastic lens mentioned above is now obsolete and should not be considered for new applications.

The replacement lens is Optima part number 300-0330-780 this P/N is the basic unmounted plastic lens.  There are also two mounted versions available – P/N 302-0330-780 (which is used in the Laser Diode Mounting Kit's P/N LDM 4300 and LDM 4356 KIT). The 302-0330-780 is intended to be a direct replacement for customers that were previously using the 302-0380-780 lens.  Another mounted version P/N 303-0330-780 is also available; this is a compact mount which is not compatible with the Laser Diode Mounting Kits and therefore not intended as a replacement for the 302-0380-780 lens.
This may be confusing... click on the part number in the tables below for the PDF data sheet.  In this case, a picture should definitely help clear up the confusion. The data for the 300-0380-780 and 302-0380-780 lenses has been left in the tables for reference only – no stock available.

Part number 300-0340-780 is an intended replacement for Optima's P/N 300-0355-780 and 300-0360-780

Optima's 300-0360-780 and 300-0355-780 were very popular lenses when laser diodes began finding application in products besides CD players.
Thirty years later we're often asked for a similar replacement – because their physical size made them very easy to handle.

Injection Molded Aspheric Lens Specifications: 

Part Number (unmounted lens) 300-0330-780 300-0340-780 300-0380-780 300-0395-780
Unit price (Qty 1-49) $3.90 $4.10 $4.70 — NLA $4.20
Description Injection Molded Plastic Aspheric Lens, unmounted
Conjugate Distance Infinite
Design Wavelength 660 / 780 nm 780 nm
Focal Length 3.05 / 3.07 mm 3.851 mm 3.40 mm 16 mm
Working/Source Distance 1.68 / 1.43 mm 2.131 mm 1.43 mm 13.79 mm
Numerical Aperture 0.662 /0.53 0.45 0.471 0.144
Clear Aperture 4.04 / 3.254 mm 3.47 mm 3.20 mm 4.60 mm
F# 0.775 / 0.943 1.10 1.06 3.48
Field Size (diameter) *   0.150 mm 0.559 mm
AR Coating, MgF2 780 nm
Transmission > 95% > 97% > 95% > 97%
Cover Glass Thickness 0.6 / 1.2 mm 1.2 mm 1.2 mm 1.25 mm
Cover Glass Index (n) 1.58 / 1.57 1.55 1.55 1.51
Temperature Range Storage Temperature -30 ~ +75 ºC         Working Temperature -10 ~ +65 ºC
Dimensions (diameter x length) Ø5.0 x 1.73 mm Ø7.4 x 3.4 mm Ø5.0 x 2.11 mm Ø6.5 x 2.33 mm

* The Field Diameter of a collimating lens defines the largest size emitter the lens will accommodate and still maintain other optical specifications,
such as the wavefront aberration specification. 

Example:  If the field diameter specification is 100 microns, then the size of the laser diode emitter must be less than 100 microns in either axis.  Generally, when using lower powered diodes (1mW to 100mW) the emitter size is not a concern, as the emitter is typically only a few microns in the perpendicular or parallel axis.  When using higher power diodes, diodes arrays, or LED's the emitter can be significantly larger – emitters larger than 100 microns are common.

Mounted Injection Molded Aspheric Lens Specifications:  

The unmounted plastic lenses listed above are available in a black anodized aluminum mount with a .375-64 external thread. The extra-fine pitch thread allows precise adjustment of the lens when collimating or focusing the beam.  

Part Number (thread mount) 302-0330-780 303-0330-780 302-0340-780 303-0340-780 302-0395-780
Unit price (Qty 1-49) $12.15


$11.85 $11.05 $11.00
Description Injection Molded Plastic Aspheric Lens, with 3/8-64 Threaded Mount
Optical Specifications Basic optical specifications as listed in the following section
Dimensions  diameter Outside diameter has an extra fine pitch 3/8-64 thread
length 6.99 mm 3.81 mm 5.78 mm 4.83 mm * 3.81 mm

* TBD Not in production, final design to be determined.


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Last modified: March 31, 2019