A compact tunable 60-dB Faraday optical isolator for the near infrared

Abstract

We describe the concept and performance of a new type of tunable Faraday optical isolator for the near infrared. 60-dB isolation is achieved with three dielectric polarizers having an extinction of only 40 dB. The compact instrument does not cause an overall polarization rotation or beam displacement and gives access to all optical beams.

Terbium gallium garnet ceramic Faraday rotator for high-power laser application

“…TGG ceramics have a high Verdet constant of 36 rad∕Tm at 1 μm wavelength [8]; a high thermal conductivity coefficient κ of 4.9 W∕mK [9], similar to the value of TGG single crystal [10,11]; and excellent size scalability, obtained by using ceramics technology. These three characteristics make the material suitable for FRs under high energy with high-average-power laser operation.…”

Verdet Constant of Magneto-Active Materials Developed for High-Power Faraday Devices

“…One of the first investigations of this material dates back to 1970s, in which the TGG was proved to have higher Verdet constant [77] and higher thermal conductivity [78] than the often used Tb-doped magneto-optical glasses. Properties of the TGG crystal and its performance in the Faraday devices have been later investigated in many papers (e.g., in [17,18,49,56,79,80]). However, the TGG crystal exhibits two major disadvantages: (a) its use in the VIS region is struggling with increasing absorption losses towards the shorter wavelengths [59,61]; and (b) growth of large-aperture TGG crystals is difficult and expensive [59,61,81,82].…”

Faraday Isolators for High Average Power Lasers

“…As a result, heat release power is at least tenths of percent of transmitted laser power P 0 . (Zarubina & Petrovsky, 1992), 2 (Zarubina et al, 1997), 3 (Chen et al, 1998), 4 (Jiang et al, 1992), 5 (Kaminskii et al, 2005), 6 (Yasuhara et al, 2007), 7 (Raja et al, 1995), 8 (Barnes & Petway, 1992), 9 (Ivanov et al, 2009), 10 (Slack & Oliver, 1971), 11 (Chen et al, 1999), 12 (Wynands et al, 1992), 13 , 14 (Mueller et al, 2002), 15 (Mansell et al, 2001), 16 (Khazanov et al, 2002a), 17 (Mukhin et al, 2009), 18 (VIRGO-Collaboration, 2008), 19 (Malshakov et al, 1997), 20 (Andreev et al, 2000a), 21 (Zarubina, 2000), 22 (Davis & Bunch, 1984).…”

“…The latter two mechanisms do alter the polarization state of radiation. The temperature dependence of the Verdet constant and thermal expansion lead to changes of the phase shift between eigen polarizations which remain circular (Wynands et al, 1992). The photoelastic effect not only changes the phase shift between eigen polarizations, but also alters the eigen polarizations themselves, which become elliptical .…”