Bulklike behavior of magnetoelasticity in epitaxial Fe1−xGax thin films
Barturen, M., D. Sander, J. Milano, J. Premper, C. Helman, M. Eddrief, J. Kirschner, M. Marangolo
abstract
Bulk Fe1−xGax alloys present a strong sensitivity of the magnetostrictive properties with Ga content with maximum magnetostriction near x = 0.19. Here, we present magnetoelastic coefficients measured by the cantilever method on Fe1−xGax thin films grown by molecular beam epitaxy on GaAs(001). We find that Ga-dependent magnetoelastic coefficients in nanometer thin films are comparable in magnitude to the respective bulk values. Moreover, we compare thin films with a tetragonal structure due to a slightly preferential alignment of Ga pairs along the growth direction with and a cubic structure. It turns out that magnetoelastic coefficients are unaffected by a preferential alignment of Ga pairs along the growth direction.
Back-side-on-BOX heterogeneous laser integration for fully integrated photonic circuits on silicon
Menezo, Sylvie, Torrey Thiessen, Georgio El Zammar, Jason Mak, Jérémy Da Fonseca, Pierre Brianceau, Bertrand Szelag, Christophe Jany, Joyce K. S Poon
The 45th European Conference on Optical Communication, (2019)
abstract
We present a fabrication flow integrating lasers at the backside of silicon-on-insulator wafers. It is expected to be compatible with integration of other material-layers and reduce the variance of lasers performance. A DFB laser fabricated accordingly exhibits a total waveguide-coupled power of 60mW at 160mA/20°C.
Nanophotonic neural probes for in vivo light sheet imaging
Sacher, Wesley D., Xinyu Liu, Ilan Felts Almog, Anton Fomenko, Thomas Lordello, Fu-Der Chen, Homeira Moradi-Chameh, Azadeh Naderian, Michael Chang, Trevor M. Fowler, Taufik A. Valiante, Andres M. Lozano, Laurent C. Moreaux, Joyce K. S Poon, Michael L. Roukes
abstract
We present implantable silicon neural probes with nanophotonic waveguide routing networks and grating emitters for light sheet imaging. Fluorescein beam profiles, fluorescent bead imaging, and fluorescence brain imaging in vivo are presented
Beam-steering nanophotonic phased-array neural probes
Sacher, Wesley D., Xinyu Liu, Fu-Der Chen, Homeira Moradi-Chameh, Ilan Felts Almog, Thomas Lordello, Michael Chang, Azadeh Naderian, Trevor M. Fowler, Eran Segev, Tianyuan Xue, Sara Mahallati, Taufik A. Valiante, Laurent C. Moreaux, Joyce K. S Poon, Michael L. Roukes
abstract
We demonstrate the first implantable nanophotonic neural probes with integrated silicon nitride phased arrays. Coherent beam-steering is achieved in brain tissue by wavelength tuning. Beam profiles, optogenetic stimulation, and functional imaging are validated in vitro.
Visible-light silicon nitride waveguide devices and implantable neurophotonic probes on thinned 200 mm silicon wafers
Sacher, Wesley D., Xianshu Luo, Yisu Yang, Fu-Der Chen, Thomas Lordello, Jason C. C Mak, Xinyu Liu, Ting Hu, Tianyuan Xue, Patrick Guo-Qiang, Michael L. Roukes, Joyce K. S Poon
abstract
We present passive, visible light silicon nitride waveguides fabricated on ≈ 100 μm thick 200 mm silicon wafers using deep ultraviolet lithography. The best-case propagation losses of single-mode waveguides were ≤ 2.8 dB/cm and ≤ 1.9 dB/cm over continuous wavelength ranges of 466-550 nm and 552-648 nm, respectively. In-plane waveguide crossings and multimode interference power splitters are also demonstrated. Using this platform, we realize a proof-of-concept implantable neurophotonic probe for optogenetic stimulation of rodent brains. The probe has grating coupler emitters defined on a 4 mm long, 92 μm thick shank and operates over a wide wavelength range of 430-645 nm covering the excitation spectra of multiple opsins and fluorophores used for brain stimulation and imaging.
Backside-processed III-V-on-silicon discrete mode laser
Thiessen, Torrey, Jeremy Da Fonseca, Jason C. C Mak, Georgio El Zammar, Christophe Jany, Bertrand Szelag, Joyce K. S Poon, Sylvie Menezo
abstract
We demonstrate the first backside-processed hybrid silicon discrete mode laser. It operates in the O-band with a total waveguide-coupled output power > 43 mW, 850 kHz linewidth, and a side mode suppression ratio of 60 dB.