Showing papers by "Amnon Yariv published in 2008"
TL;DR: In this article, a silicon/III-V hybrid semiconductor waveguide structure for laser oscillation is analyzed and it is shown that by optimally designing and controlling the resonant supermode behavior in such structures, the modal gain can be enhanced five times compared with that of the existing silicon evanescent laser, while maintaining efficient coupling to outside silicon waveguide circuits.
Abstract: We analyze a silicon/III-V hybrid semiconductor waveguide structure for laser oscillation. We show that, by optimally designing and controlling the resonant supermode behavior in such structures, the modal gain can be enhanced five times compared with that of the existing silicon evanescent laser, while maintaining efficient coupling to outside silicon waveguide circuits.
52 citations
TL;DR: An extended analysis and experimental support of a concept for a classical key generation system, based on establishing laser oscillation between two parties, is presented, which is realized using standard fiber-optic components.
Abstract: The secure distribution of a secret key is the weakest point of shared-key encryption protocols. While quantum key distribution schemes could theoretically provide unconditional security, their practical implementation remains technologically challenging. Here we provide an extended analysis and present an experimental support of a concept for a classical key generation system, based on establishing laser oscillation between two parties, which is realized using standard fiber-optic components. In our Ultra-long Fiber Laser (UFL) system, each user places a randomly chosen, spectrally selective mirror at his/her end of a fiber laser, with the two-mirror choice representing a key bit. We demonstrate the ability of each user to extract the mirror choice of the other using a simple analysis of the UFL signal, while an adversary can only reconstruct a small fraction of the key. The simplicity of this system renders it a promising alternative for practical key distribution in the optical domain.
42 citations
TL;DR: A theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers is developed and it is demonstrated that disk Bragg resonator lasers have the highest quality factor, the highest emission efficiency, and the smallest modal area, indicating their suitability in low-threshold, high-efficiency, ultracompact laser design.
Abstract: We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysis, we obtain the modal properties of circular DFB, disk-, and ring- Bragg resonator lasers. We also compare the threshold gain, single mode range, quality factor, emission efficiency, and modal area of these types of circular grating lasers. It is demonstrated that, under similar conditions, disk Bragg resonator lasers have the highest quality factor, the highest emission efficiency, and the smallest modal area, indicating their suitability in low-threshold, high-efficiency, ultracompact laser design, while ring Bragg resonator lasers have a large single mode range, high emission efficiency, and large modal area, indicating their suitability for high-efficiency, large-area, high-power applications.
25 citations
TL;DR: It is reported that the first room temperature CW operation of two dimensional single-mode edge-emitting photonic crystal Bragg lasers with single-lobed, diffraction limited far-fields is obtained.
Abstract: We report the first room temperature CW operation of two dimensional single-mode edge-emitting photonic crystal Bragg lasers. Single-mode lasing with single-lobed, diffraction limited far-fields is obtained for 100µm wide and 550µm long on-chip devices. We also demonstrate the tuning of the lasing wavelength by changing the transverse lattice constant of the photonic crystal. This enables a fine wavelength tuning sensitivity (change of the lasing wavelength/change of the lattice constant) of 0.072. This dependence proves that the lasing mode is selected by the photonic crystal lattice.
19 citations
TL;DR: In this paper, an electronic feedback scheme using a voltage controlled oscillator (VCO) to control the optical phase of individual semiconductor lasers (SCLs) phase locked to a common reference laser using heterodyne optical phase-locked loops (OPLLs) was demonstrated.
Abstract: In this letter, we demonstrate the use of an electronic feedback scheme using a voltage controlled oscillator (VCO) to control the optical phase of individual semiconductor lasers (SCLs) phase locked to a common reference laser using heterodyne optical phase-locked loops (OPLLs). The outputs of two external cavity SCLs phase-locked to a common reference laser are coherently combined, and the variation in the relative optical path lengths of the combining beams is corrected by dynamically changing the phase of the offset radio-frequency signal fed into one of the OPLLs by means of a VCO. A stable power combination efficiency of 94% is achieved. This inherently different method of phase control, i.e., electronic rather than the use of electrooptic crystals, is deemed essential for new applications involving coherent optoelectronics.
18 citations
Patent•
26 Apr 2008TL;DR: In this paper, a III-V semiconductor waveguide is coupled with a Si waveguide to form a hybrid structure, and the spatial location of the optical mode (or supermode) of the hybrid structure is controlled by controlling at least one between the geometry and the refractive index of the structure.
Abstract: A III-V semiconductor waveguide is coupled with a Si waveguide to form a hybrid structure. Spatial location of the optical mode (or supermode) of the hybrid structure is controlled by controlling at least one between the geometry and the refractive index of the structure, e.g., varying width of the Si waveguide. Control of such spatial location allows location of the optical mode either almost entirely in the III-V semiconductor waveguide or almost entirely in the Si waveguide, thus allowing various optical arrangements to be obtained according to the location of the optical mode and the proprieties of the waveguides. For example, if the III-V semiconductor waveguide is amplifying and is provided with a highly reflective mirror at one end, the Si waveguide is provided with a partially reflective mirror at the other end, the optical mode is almost entirely located in the gain region of the III-V semiconductor waveguide, and is also almost entirely located in the coupling region of the Si waveguide, a resonator for laser oscillation is obtained.
7 citations
TL;DR: The early work on integrated optics at the Bell Telephone Laboratories and at the California Institute of Technology (Caltech), with which the author was involved, is described from a personal perspective in this article.
Abstract: The early work (1960s, 1970s) on Integrated Optics at the Bell Telephone Laboratories and at the California Institute of Technology (Caltech), with which the author was involved, is described from a personal perspective.
5 citations
TL;DR: In this paper, the authors demonstrate two electron beam lithography techniques in a process for the fabrication of surface structure lasers with large areas that require sub-micron to nanometer accuracy.
5 citations
12 Feb 2008
TL;DR: In this article, the authors derive a coupled-mode theory for the analysis of non-periodic grating circular Bragg lasers and derive an optimal design for the microdisk laser to achieve both strong confinement and efficient vertical emission.
Abstract: We derive a comprehensive coupled-mode theory, including resonant vertical radiation, for the analysis of non-periodic grating circular Bragg lasers. We analyze the threshold levels and modal properties of such lasers employing mixed-order Bragg gratings to achieve both strong confinement and efficient vertical emission. By reducing the threshold gain and maximizing the emission efficiency, we suggest an optimal design for the circular Bragg microdisk lasers which indicates low-threshold and high-efficiency operation is possible.
2 citations
TL;DR: This work proposes and demonstrates a novel CBC servo system using optical phase lock loops for phase control based on entirely electronic components and, consequently, can be considerably more compact and less expensive compared to servo systems made of optical phase/frequency shifters.
Abstract: Coherent Beam Combining (CBC) technology holds the promise of enabling laser systems with very high power and near-ideal beam quality. In this work we propose and demonstrate a novel CBC servo system using optical phase lock loops for phase control. This servo system is based on entirely electronic components and, consequently, can be considerably more compact and less expensive compared to servo systems made of optical phase/frequency shifters. In the proof-of-concept experiments we have combined two 100mW 1064nm commercial semiconductor lasers with the filled-aperture approach at an efficiency of 94% and also two 50mW 1538nm commercial semiconductor lasers using the tiled-aperture approach with a strehl ratio of 0.9. In addition, we also present a theoretical consideration of the influence of various sources of noise on the combining efficiency of a cascaded filled-aperture CBC system.
2 citations
04 May 2008
TL;DR: In this article, a new type of optical mode that possesses a formal analogy to the dark atomic state involved in electromagnetically induced transparency is proposed, which displays a transparency and slow light behavior free from the bandwidth-delay product constraint.
Abstract: A new type of optical mode that possesses a formal analogy to the dark atomic state involved in electromagnetically induced transparency. It displays a transparency and slow light behavior free from the bandwidth-delay product constraint.
TL;DR: Ultra-long fiber laser system for secure key generation is demonstrated, using standard components only, and 1000 bits are shared between users 25km apart, with 0.5% errors.
Abstract: Ultra-long fiber laser system for secure key generation is demonstrated, using standard components only. 1000 bits are shared between users 25km apart, with 0.5% errors. Time and frequency domain attacks could not extract the key.
25 Nov 2008
TL;DR: In this paper, the authors analyze modal properties of surface-emitting annular Bragg lasers and suggest design guidelines with numerical demonstration of large-area, high-efficiency, single-mode lasing in such lasers.
Abstract: Including the effect of vertical resonant emission, we analyze modal properties of surface-emitting annular Bragg lasers and suggest design guidelines with numerical demonstration of large-area, high-efficiency, single-mode lasing in such lasers.
TL;DR: By a comprehensive coupled-mode approach, this paper pinpointed a flaw in the previous design guidelines of vertically-emitting annular Bragg lasers and suggested new design guidelines with numerical demonstration of large-area, high-efficiency, single-defect mode lasing.
Abstract: By a comprehensive coupled-mode approach, we pinpoint a flaw in the previous design guidelines of vertically-emitting annular Bragg lasers and suggest new design guidelines with numerical demonstration of large-area, high-efficiency, single-defect mode lasing.
04 May 2008
TL;DR: In this article, the first room temperature CW operation of two dimensional single-mode edge-emitting photonic crystal Bragg laser was reported for 100mum wide and 550m long on-chip devices.
Abstract: We report the first room temperature CW operation of two dimensional single-mode edge-emitting photonic crystal Bragg lasers. Single-mode lasing with single-lobed, diffraction limited far-fields is obtained for 100mum wide and 550 mum long on-chip devices.
13 Jul 2008
TL;DR: In this paper, a new propagating optical mode in a bi-perodic wavegide was described, which possesses a dark-mode in formal analogy to the Dark atomic state of EIT.
Abstract: We describe a new propagating optical mode in a bi-perodic wavegide. It possesses a Dark-Mode in formal analogy to the Dark atomic state of EIT. It displays transparency and slow-light behavior free from bandwidth-delay product-constraint.