IO-5-405-LP In Stock

The IO-5-405-LP by ThorLabs is a free-space isolator, an advanced device designed to mitigate the negative effects of optical feedback in laser systems. By reducing or eliminating the reflections of a laser's energy back into itself, this device ensures that the laser operates smoothly and efficiently, without suffering from noise, laser damage, and amplitude fluctuation.

Optimized for use in the visible spectral range of 390 nm - 700 nm, the IO-5-405-LP is engineered to protect the laser while maintaining beam alignment and providing maximum forward transmission and reverse isolation. The construction of a Faraday rotator comprised of a magnetic field-encased magneto-optic central black cylinder plus at least two polarizer cells is found at the ends. These polarizer cells have lines that are engraved which designate the axis of polarization, enabling the device to transmit light along a single direction and shield upstream optics from back reflections.

Back reflections can lead to a range of instabilities in light sources, including noise, frequency shifts, mode hopping, loss of mode lock, and permanent damage of the optic. The IO-5-405-LP solves this problem by blocking any reflections that might interfere with your laser, thereby preventing any negative effects. The device is mounted in a black slip ring with an 8-32 tapped hole for post mounting, and its housing is marked with an arrow that indicates the direction of forward propagation for user convenience.

The IO-5-405-LP is an adjustable narrowband isolation that allows you to adjust the alignment of the input and output polarizers, giving you the ability to tune the central wavelength for maximum isolation. With this feature, the isolator can be fine-tuned to ensure that 97% of peak transmission is preserved and complete isolation is maintained, even if the laser's output varies by ±5% of its central wavelength.

The IO-5-405-LP has two modes of operation: forward mode and reverse mode. In forward mode operation, laser light enters the isolator via the input polarizer, is linearly polarized, and then enters the rotator, which rotates the plane of polarization by +45°. In reverse mode operation, a portion of the random beam reflections will be directed back towards the laser. After going through the isolator, the feedback is re-directed and polarized in the output polarizer at 45° relative to the initial beam. The beam is then rotated +45° by the rotator, and the feedback, now polarized at 90° relative to the input polarizer, is extinguished, effectively isolating the laser from its own reflections.