Abstract: A high power Faraday isolator or rotator includes, at least one Faraday optical element, and a magnetic structure capable of generating a magnetic field within the at least one Faraday optical element. The at least one Faraday optical element comprises a Potassium Terbium Fluoride (KTF) crystal grown or manufactured along the [113] crystal orientation and which is oriented such that the light propagating through the Faraday isolator is within 2 degrees of the [113] crystal orientation.

Abstract: A multi-pass-type Faraday rotator useful in an optical isolator is provisioned with high-efficiency, high-field permanent magnets formed with minimal magnetic material. A high magnetic field is generated by two sets of magnets attached to outer pole plates that are mirror images of each other. Like-type poles of the magnets in each set are disposed against each other above and below the beam path plane of a multi-pass Faraday optic. Each set of magnets is formed of a central block of magnetic material with magnetization oriented substantially parallel to the multi-pass beam path on the Faraday optic, adjoined by adjacent blocks of magnetic material with magnetization oriented substantially perpendicular to the central magnet block and with like poles to the central magnet block where the magnets border the multi-pass Faraday optic.

Abstract: Faraday rotator or isolator with mode stripping ferrules and collimators having fiber pigtailed mode stripping components. An example is a compact Faraday Isolator module employing mode stripping ferrules and mode stripping collimators at the input and/or at the output of a fiber pigtailed Faraday Isolator. Two basic isolator types are a Polarization Independent Faraday isolator and a Polarization Maintaining Faraday isolator. The device is substantially immune to damage due to back-reflection, thermal lensing, energy leakage and absorption. Mode stripped optical energy propagating in the reverse direction is diverted onto a heat absorbing and heat sinking structure, as for example at the input of a compact birefringent wedge-based PI isolator. Alternatively, the optical energy propagating in the reverse direction is angularly refracted away from the forward incident beam path and is coupled into the energy dispersive cladding of the input fiber or the ferrule itself.

Abstract: Faraday rotator or isolator with mode stripping ferrules and collimators having fiber pigtailed mode stripping components. An example is a compact Faraday Isolator module employing mode stripping ferrules and mode stripping collimators at the input and/or at the output of a fiber pigtailed Faraday Isolator. Two basic isolator types are a Polarization Independent Faraday isolator and a Polarization Maintaining Faraday isolator. The device is substantially immune to damage due to back-reflection, thermal lensing, energy leakage and absorption. Mode stripped optical energy propagating in the reverse direction is diverted onto a heat absorbing and heat sinking structure, as for example at the input of a compact birefringent wedge-based PI isolator. Alternatively, the optical energy propagating in the reverse direction is angularly refracted away from the forward incident beam path and is coupled into the energy dispersive cladding of the input fiber or the ferrule itself.

Abstract: A monolithic ferrule/endcap/optical fiber structure is provided wherein an optical fiber is terminated in a ferrule and bonded by fusion to form a monolithic unit which minimizes optical loss and is typically capable of transmitting high power laser radiation, preferably on the order of 500 W and higher, without damage to the optical fiber and ferrule. Ferrule, endcap, optical fiber and fusible powder are composed of material of substantially the same physical characteristics such that, when all are fused together, the structure so formed is monolithic and the optical path is transparent.