Pockel’s effect and optical rectification in (111)-cut near-intrinsic silicon crystals

Abstract

Pockel’s effect and optical rectification are demonstrated in the charge space region of a (111)-cut near-intrinsic silicon crystal by the use of a planar metal-insulator-semiconductor structure. The results show that both Pockel’s effect and optical rectification are so considerable that these effects should be taken into account for designing silicon-based photonic devices. The anisotropy of optical rectification is measured too, and experimental results are in good accordance with the theoretical analysis. These effects can also be used as a tool to investigate the properties of the charge space region of silicon devices in future.

Optical rectification in self-assembled monolayers probed at surface plasmon resonance condition

“…A few experimental works reported OR in NLO crystals in 1960s. [1][2][3][4] However there have been few reports on the OR effect since then, 5,6 in contrast to the other second-order NLO phenomena such as second-harmonic generation ͑SHG͒ and the linear electrooptic effect ͑EO͒. This is because it was recognized that OR effects had not been directly applicable to optical devices.…”

Optical rectification and Pockels effect as a method to detect the properties of Si surfaces

“…Stress-induced PE and second-harmonic generation (SHG) have been found recently in strained Si [6][7][8][9][10] . Local electric-field-induced (EFI) second-order nonlinear optical effects, such as EFI SHG [11,12] , EFI PE, and EFI OR [13][14][15] , were observed. EFI SHG and EFI second-harmonic spectroscopy have been widely used for characterization of Si-SiO 2 interfaces in metal-oxide-semiconductor (MOS) devices [16][17][18][19][20][21][22][23][24] .…”

Experimentally distinguishing electro-optic ef fects in silicon

“…In addition to KE, PE should also be taken into account at the surfaces or interfaces of silicon. As for (111)-Si crystals, 3 m symmetry has been verified at the surfaces of silicon [11,19] , and the optical axis is the [111] axis. Therefore, under the electric field E = E m cos(Ωt) along the [111] direction, silicon surfaces remain uniaxial, and the orientations of the principal axes are unchanged.…”

“…However, near the surfaces and interfaces or in the space charge regions of silicon, the inversion symmetry of silicon can be broken naturally or by built-in electric field [14,15] and strain [16,17] . Therefore, the electric-field-induced [11,18] or strain-induced [19,20] PE can also take place in silicon. Both PE and KE are able to produce the birefringence in silicon.…”

“…Electrooptic effects have faster response than thermo-optic effects; thus, they are the more promising mechanisms of silicon optical modulators. The electro-optic effects in silicon can be classified into two types: 1) direct electrooptic effects such as Kerr effect (KE) [10] and Pockels effect (PE) [11] , by which the applied electric field can change the real part of the refractive index directly, and 2) indirect electro-optic effects such as Franz-Keldysh effect (FKE) [12] and plasma dispersion effect (PDE) [13] , by which the applied electric field is able to alter the absorption coefficient or the imaginary part of the refractive index, thereby also indirectly changing the real part of the refractive index according to the KramersKronig relations. PDE is generally much stronger than other electro-optic effects in doped silicon.…”