Technical Data Sheet



635nm Visible Light Source

The KD Optics VLS-40 is an easy to use, hand-held, visible source used for testing fibre optic cable installations. It is especially useful when testing fibre optic cables close to the terminal equipment. The unit is pocket sized with a long battery life, making it ideal for local fault finding and continuity checking of fibres.


The output wavelength is 635nm, which is approximately nine times brighter than other units operating at 670nm, which means a break or loss is much easier to see; the light will even pass through jacketed cables containing kevlar.



VLS40 Visible Light Source

635nm Visible Laser

Local fault finding around the ODF

Small compact hand held unit

Fibre continuity testing

Exceptionally long battery life

Fibre tracing

Low cost

Visual alignment of mechanical splices

Eliminates the need for an OTDR in many cases

Visual location of faults in patch panels, splice trays etc.

Singlemode or multimode

Long battery life

VLS40 Visible Laser Specifications


VLS40 Visible laser source

Source Type



635nm typical

Output power level

Max. 0.85mW, (9/125)

Fibre type

Singlemode or multimode


Continuous or Flash at 2Hz

Battery type

2 x AA rechargeable NiMh (supplied) or Alkaline cells

Battery life

50 hours approx. continuous (Alkaline) 80 hours approx. in flash mode (Alkaline)

Power requirements

Charger will operate the unit when batteries are flat and charge NiMh cells when fitted (Supplied)

Optical Connector

Fixed FC/PC, ST, SC, Diamond etc.


Class 2

Temperature range

0 - 50° C


152 x 83 x 33mm



VLS40 Ordering Information

VLS40X 635nm Visible light source

e.g. VLS40PC specifies a VLS40 with an FC/PC
output connector.

 VLS40 Standard accessories

Manual, Carrying pouch, AC charger
One year warranty

VLS40 Optional accessories

Spare AC charger
Bare fibre adapter
Test cables
Small carry case for 2 instruments and accessories
Large carry case for 3 instruments and accessories



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KD Optics Design and Engineering Ltd, New Forest Farm, Walshford, North Yorkshire LS22 5JJ, UK
Tel +44 ( 0 ) 1937 587003, Fax +44 ( 0 ) 1937 587002, e-mail

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