Tunable non-reciprocal components with ferrites that can be integrated using a foundry suitable process are key to achieving low-power adaptive microwave circuits. The current state-of-the-art still relies on electrical tuning or resistive absorbers to facilitate unidirectional propagation. Here, we demonstrate a novel process for spin-coating thick films of ferrites without the complexities of vacuum processes or high-temperature annealing. Composites of yttrium iron garnet (YIG) nanoparticles in a matrix spin-on-glass are spin-coated on silicon substrates, and magnetic properties comparable to bulk YIG are obtained in films exceeding 30 microns. We also propose a design for tunable phase shifter based on periodically serrated coplanar waveguide with a YIG cladding. A nonreciprocal phase difference of 20 – 60 degrees is obtained over a tunable band of 550 MHz between 3.85 - 4.4 GHz from a tuning magnetic field of 8 – 40 kA/m.
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Magneto‐Optical Bi:YIG Films with High Figure of Merit for Nonreciprocal Photonics
Thin film magneto‐optical (MO) materials are enablers for integrated nonreciprocal photonic devices such as isolators and circulators. Films of polycrystalline bismuth‐substituted yttrium iron garnet (Bi:YIG) have been grown on silicon substrates and waveguide devices, in which an yttrium iron garnet (YIG) seedlayer is placed either above or below the active Bi:YIG layer to promote crystallization. The films exhibit a high MO figure of merit of up to 769° dB−1at 1550 nm wavelength. Growth of single phase Bi:YIG on the sidewalls of waveguides is demonstrated, which can be used in nonreciprocal transverse electric (TE)‐mode devices.
more » « less- NSF-PAR ID:
- 10125000
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 7
- Issue:
- 13
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Rare‐earth iron garnets (REIG) have recently become the materials platform of choice for spintronic studies on ferrimagnetic insulators. However, thus far the materials studied have mainly been REIG with a single rare earth species such as thulium, yttrium, or terbium iron garnets. In this study, magnetometry, ferromagnetic resonance, and magneto‐optical Kerr effect imaging is used to explore the continuous variation of magnetic properties as a function of composition for Y
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