Chapter 3 Description - THORLABS IO-F-660 User Manual

660 nm Fiber Isolator

Chapter 3 Description

Fiber isolators protect light sources from back reflections and signals that can
cause intensity noise and optical damage. Optical isolators, also known as
Faraday isolators, are magneto-optic devices that preferentially transmit light in
the forward direction while absorbing or displacing light propagating in the
reverse direction.
This Thorlabs' polarization-independent isolator is compatible with single mode
(SM) fibers. There is 0.8 m to 1.0 m of fiber built in to each side of the isolator,
and an arrow engraved on the body indicating the transmission direction. In
addition, each unit is tested before shipment to ensure compliance with our
specifications and a complete test report comes with every serialized part.
An isolator consists of a Faraday rotator, at least two polarizers, a half-wave
retarder and collimating lenses.
The main body of the isolator contains the Faraday rotator, polarizers and
retarder. The outer aluminum sleeves protect the input and output ports
containing the collimating lens and fiber ferrule.
This isolator is mounted on a baseplate with two 4-40 (M3) counterbored slots for
securing the unit to a breadboard or optical table. This base may be removed by
the user if desired. However, do not remove the lid as this is considered
disassembling and will void the warranty.
Part Number
The part number consists of the following:

IO (The Isolator Code)

Letter
o Polarization dependence (F/K – Independent; J/L – Dependent)
o Maximum Power Level (F/J – 0.5W CW max; K/L - 10W CW max)

Center Wavelength (nm)
Example: The IO-F-660 isolator is a polarization independent fiber isolator
with a max power level of 0.5 W (CW) and a center wavelength of 660 nm.
Rev B, Sept. 14, 2018
Chapter 3: Description
Page 3