The apparatus employs an optical switch at the launch end of the optical fiber to be tested and another optical switch at the output end of the optical fiber to be tested.

The interface ports and optical backplane within the optical switch contain an optical splitter and optical coupler and additionally space for a second selective switch.

An optical switch using a refractive optical element (52) to direct a light beam in selected directions upon operation of the switch.

The optical signal router also includes an optical switch (102) having an electrical modulation input (106) that is electrically coupled to the output (122) of the switch driver.

In a first state of an optical switch, a structure in the switch confines an optical mode to propagate along a first, unswitched path.

The assembly includes first and second groups of optical paths, and first and second optical switches.

The optical switch is a Mach-Zehnder interferometer optical switch composed of photonic crystal line-defect waveguides.

The PD array is integrated inside the core optical switch, so that the architecture and the volume of the optical switch are simplified.

An optical switch which is easily manufactured and produces little optical loss.