All-optical silicon-based integrated fiber-optic modulator, logic gate, and self-limiter

1988 ◽  
Vol 66 (10) ◽  
pp. 833-840 ◽  
Author(s):  
R. Normandin ◽  
D. C. Houghton ◽  
M. Simard-Normandin ◽  
Y. Zhang
Keyword(s):  
Fiber Optics ◽  
Logic Gate ◽  
Single Mode ◽  
Bandgap Energy ◽  
Optical Mode ◽  
All Optical ◽  
Recovery Times ◽  
Mode Cutoff ◽  
Silicon Based ◽  
Optical Silicon

We describe an all-optical mode cutoff modulator for use in fiber optics systems working at wavelengths in the 1.3–1.6-μm range. The active waveguide is silicon grown by molecular beam epitaxy, and the channels are fabricated by conventional lithographic techniques and used with standard single-mode fibers. Subnanosecond initiation and recovery times are achieved with less than 150 pJ of control energy in a three-port geometry suitable for use as a logic gate. We also present preliminary results when the guided light is near the bandgap energy and demonstrate self-limiting for integrating Kerr-like self-defocussing nonlinearities. In both cases, the operation of the device is largely wavelength independent and stable.

scholarly journals Photo-Excited Silicon-Based Spatial Terahertz Modulators

2021 ◽  
Vol 14 (1) ◽  
pp. 1-19
Author(s):  
Yu-Lian He ◽  
Yuan-Sheng Wang ◽  
Qi-Ye Wen
Keyword(s):  
High Performance ◽  
Imaging Spectroscopy ◽  
Cost Effective ◽  
Thz Radiation ◽  
All Optical ◽  
Potential Applications ◽  
Modulation Rate ◽  
Silicon Based ◽  
Optical Silicon ◽  
Novel Design

The increasing development of terahertz (THz) technology has led to various potential applications in THz imaging, spectroscopy and communications. These devices capable of actively manipulating the amplitude, phase and frequency of THz waves are thus gaining numerous interests. All-optical silicon-based spatial terahertz modulators (STMs), as a simple, cost-effective, and reconfigurable technique, are standing the focus of research. Beginning with a fundamental concept of THz radiation, this paper systematically summarized the modulation mechanism and theoretical model for this kind of STM, reviewed the recent advancements in THz functional devices implemented by this optical method and yet, discussed the performance-improved measures with an emphasis on the reflection reduction. Despite that, there has been considerable progress in realizing high-performance STMs, and novel design is urgent to realize higher modulation rate and more functionality.

All-optical logic in fiber systems using nonlinear refraction

1987 ◽  
Vol 65 (8) ◽  
pp. 913-918 ◽  
Author(s):  
R. Normandin
Keyword(s):  
Fiber Optics ◽  
Communication Systems ◽  
Logic Gate ◽  
Nonlinear Refraction ◽  
Contrast Ratio ◽  
Optical Logic ◽  
Physical Mechanisms ◽  
All Optical ◽  
Wavelength Control ◽  
Logic Functions

We describe the realization of a nonlinear all-optical logic gate and modulator for use in fiber-optics communication systems. The physical mechanisms for the optical nonlinearities and their influences on device operation and design are considered. Results are presented for the AND, NOR, NOT, and XOR logic functions with a better than 20 dB contrast ratio. The gates and modulators exhibit exceptional stability, because no resonator, feedback, or stringent wavelength control are needed. Silicon at λ = 1.06 μm has been used for these "proof-of- concept" experiments. The feasibility of picosecond operation, multiplexing, and wavelength translation is discussed.

All-optical, silicon based, fiber optic modulator using a near cutoff region

1989 ◽  
Vol 67 (4) ◽  
pp. 412-419 ◽  
Author(s):  
R. Normandin ◽  
D. C. Houghton ◽  
M. Simard-Normandin
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Logic Gate ◽  
Chemical Vapour ◽  
Single Mode ◽  
Optical Modulator ◽  
Time Resolved ◽  
Graded Index ◽  
Silicon Thin Films ◽  
All Optical

We demonstrate, using molecular beam epitaxy and chemical vapour deposition grown silicon thin films, an all-optical modulator for single-mode guided light at 1.32 μm. A control beam of above band-gap light is used to generate electron–hole pairs via inter-band absorption and the resultant lowering of the effective refractive index brings the waveguide to cutoff thus limiting throughput. Near 100% modulation is obtained with less than 150 pJ energies with subnanosecond initiation and recovery times. The operation is stable and is polarization and wavelength independent in a three port geometry suitable for use as a logic gate. To reduce the total energy required to bring the waveguide to cutoff, the effects of using a small, already near cutoff and leaky region at the interaction region is investigated here. Preliminary measurements on a graded index, leaky mode, chemical vapour deposition sample resulted in a reduction by a factor of five or better in drive energy. By keeping the leaky region short, the losses can be kept to negligible values. Results in time resolved imaging of the guided mode are also presented along with the necessary design considerations for performance compatible with presently available communication solid state laser sources.

Photonic crystal based on mott phase change material as all-optical bandgap switch and composite logic gate

2021 ◽  
Vol 113 ◽  
pp. 110855
Author(s):  
Lei Zhang ◽  
Yuanhe Sun ◽  
Zhenjiang Li ◽  
Lin Wang ◽  
Shuqi Cao ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Phase Change ◽  
Phase Change Material ◽  
Logic Gate ◽  
Optical Bandgap ◽  
All Optical ◽  
Mott Phase ◽  
Change Material
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