Optical isolation in Cd_1−xMn_xTe magneto-optical waveguide grown on GaAs substrate

Abstract

The isolation effect was studied in a Cd 1Ϫx Mn x Te magneto-optical waveguide grown on a GaAs substrate. By use of prism coupling, an isolation ratio of 20 dB was achieved at ϭ 740 nm under a magnetic field of 5 kG. The high isolation ratio obtained in the magneto-optical waveguide grown on the semiconductor substrate shows the feasibility of monolithical integration of an optical isolator with semiconductor optoelectronic devices.

( Cd , Mn ) Te ∕ ( Cd , Zn ) Te quantum well waveguide optical isolator with wide wavelength operational bandwidth

“…For practical applications, the mode conversion efficiency should be at least 95% to achieve a high isolation ratio of 25 dB. 2,14,15 Figure 4 shows the wavelength range within which more than 95% conversion efficiency was obtained for the waveguide with single QW as a function of well width. For well widths of 20-40 Å, the operational wavelength range is as wide as 25 nm.…”

“…13 The optical isolator uses the 45°rotation of the linearly polarized light due to the Faraday effect. 9,14 As the Faraday rotation in ͑Cd,Mn͒Te changes with wavelength, the rotation angle of the polarization plane deviates from 45°r esulting in severe performance degradation of the isolator. Because Faraday rotation of paramagnetic ͑Cd,Mn͒Te is proportional to the applied magnetic field, it is possible to compensate for the large wavelength dependence of the Faraday rotation in ͑Cd,Mn͒Te by tuning an external magnetic field for each operated wavelength.…”

Complete magneto‐optical TE‐TM mode conversion in Cd1–xMnxTe waveguide for integrated optical isolator

“…A high isolation effect can be achieved for a waveguide with high magneto-optical mode conversion ratio [13]. We define isolation ratio as the difference between forward and backward transmission of the two-prism coupling [11]. Figure 4(a) shows the transmission coefficient for forward (open squares) and backward (solid squares) propagations as a function of the magnetic field for light propagation length, L = 4 mm and λ = 740 nm.…”

“…1 (c). To measure the isolation effect, two GaP prisms were used for coupling the light into and from the waveguide [11]. The axes of polarizer and analyzer were adjusted so that the angle between them was 45°.…”

Magneto-optical mode conversion in a hybrid glass waveguide made by sol-gel and ion-exchange techniques

“…The second is the development of novel magneto-optical materials compatible with classical technologies. In this way, lots of efforts have been made to obtain such materials compatible with semi-conductor substrate [5,6,7,8]. Nevertheless, no approach has allowed the full integration of a magnetooptical material with glassy material waveguides which can not stand temperature higher than 500°C.…”