Showing papers by "Amnon Yariv published in 2007"
Book•
01 Jan 2007
TL;DR: In this article, KRAMERS-KRONIG this article describes the step-index CIRCULAR WAVEGUIDE and the transformation of a COHERENT ELECTROMAGNETIC FIELD by a thin LENS.
Abstract: 1. Electromagnetic Fields and Waves 2. Rays and Optical Beams 3. Dielectric Waveguides and Optical Fibers 4. Optical Resonators 5. Interaction of Radiation and Atomic Systems 6. Theory of Laser Oscillation and Some Specific Laser Systems 7. Chromatic Dispersion and Polarization Mode Dispersion in Fibers 8. Nonlinear Optics 9. Electro-Optics and AO modulators 10. Noise in Optical Detection and Generation 11. Detection of Optical Radiation 12. Periodic Structures 13. Waveguide Coupling 14. Nonlinear Optical Effects in Fibers 15. Semiconductor Lasers 16. Advanced Semiconductor Lasers 17. Optical Amplifiers 18. Classical Treatment of Quantum Optics, Quantum Noise, and Squeezing A. WAVE EQUATION IN CYLINDRICAL COORDINATES AND BESSEL FUNCTIONS B. EXACT SOLUTIONS OF THE STEP-INDEX CIRCULAR WAVEGUIDE C. KRAMERS-KRONIG RELATIONS D. TRANSFORMATION OF A COHERENT ELECTROMAGNETIC FIELD BY A THIN LENS E. FERMI LEVEL AND ITS TEMPERATURE DEPENDENCE F. ELECTRO-OPTIC EFFECT IN CUBIC 43M CRYSTALS G. CONVERSION FOR POWER UNITS AND ATTENUATION UNITS
1,010 citations
Patent•
20 Apr 2007
TL;DR: In this article, the authors proposed a coherent opto-electronic system using semiconductor lasers driven by feedback control circuits that control the laser's optical phase and frequency, which provides a means for coherent phased laser array operation and reduced phase noise.
Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by feedback control circuits that control the laser's optical phase and frequency. Feedback control provides a means for coherent phased laser array operation and reduced phase noise. Systems and methods to coherently combine a multiplicity of lasers driven to provide high power coherent outputs with tailored spectral and wavefront characteristics are disclosed. Systems of improving the phase noise characteristics of one or more semiconductor lasers are further disclosed.
78 citations
TL;DR: A hybrid laser structure which consists of an amplifying III-V waveguide proximity-coupled to a passive Si waveguide which can cause the optical power to be confined to any of the two waveguides by control of waveguide' geometry is described.
Abstract: We describe a hybrid laser structure which consists of an amplifying III-V waveguide proximity-coupled to a passive Si waveguide. By operating near the synchronism point (where the phase velocities of the individual waveguides are equal), we can cause the optical power to be confined to any of the two waveguides. This is accomplished by control of waveguides’ geometry. In the portion of the supermode resonator where amplification takes place, the mode is confined nearly completely to III-V guide thus realizing a near maximal gain. Near the output facet, the mode power is confined to the Si waveguide thus optimizing the output coupling. This is to be contrasted with approaches which depend on evanescent field penetration into the III-V medium to obtain gain.
69 citations
TL;DR: In this paper, a servo system composed of multilevel optical phase lock loops was proposed and demonstrated for coherent beam combining (CBC) technology, which 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. We propose and demonstrate a novel servo system composed of multilevel optical phase lock loops. 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. We have also characterized the noise of a 1064 nm Yb-doped fiber amplifier to determine its effect on the CBC and studied theoretically the efficiency of combining a large array of beams with the filled-aperture implementation. In a proof-of-concept experiment we have combined two 100 mW 1064 nm semiconductor lasers with an efficiency of 94%.
42 citations
TL;DR: Current-injection optical phase-lock loops based on commercial single-section semiconductor distributed-feedback lasers are experimentally demonstrated using two parallel OPLLs and obtained 87% efficient coherent power combining of the two DFB lasers.
Abstract: We have experimentally demonstrated current-injection optical phase-lock loops (OPLLs) based on commercial single-section semiconductor distributed-feedback (DFB) lasers. Using two parallel OPLLs, we have obtained 87% efficient coherent power combining of the two DFB lasers. The rms differential phase error between the two lasers is about 30°.
42 citations
TL;DR: In this article, a transfer matrix method is used to analyze the modal gain of transverse Bragg resonance (TBR) structures and three different feedback mechanisms are proposed to select the desired TBR modes.
Abstract: We use a transfer matrix method to analyze the modal gain of transverse Bragg resonance (TBR) structures. We show that these TBR structures can support two types of modes characterized by different modal angles: small mode angle (SMA) modes and TBR modes. We discuss the origin, modal properties and field distributions of both the TBR modes and SMA modes. Three different feedback mechanisms are proposed to select the desired TBR modes.
41 citations
TL;DR: In this paper, the authors used a tight-binding formalism to analyze the effect of resonant gain enhancement and spontaneous emission noise in amplifying coupled-resonator optical waveguides (CROWs).
Abstract: We use a tight-binding formalism in the time domain to analyze the effect of resonant gain enhancement and spontaneous emission noise in amplifying coupled-resonator optical waveguides (CROWs). We find the net amplification of a wave propagating in a CROW does not always vary with the group velocity, and depends strongly on the termination and excitation of these structures. The signal-to-noise ratio and noise figure of CROW amplifiers are derived in the tight-binding formalism as well. The physical interpretations and practical consequences of the theoretical results are discussed.
29 citations
TL;DR: In this paper, the authors analyzed the transmission of light through coupled-resonator optical waveguides in the form of evanescently coupled Fabry-Perot resonator arrays and developed a transfer matrix method to calculate the amplitude and phase responses of the arrays.
Abstract: We analyze the transmission of light through coupled-resonator optical waveguides in the form of evanescently coupled Fabry-Perot resonator arrays. We develop a transfer matrix method to calculate the amplitude and phase responses of the arrays. We also discuss the inclusion of optical gain in the system to compensate for losses in these structures. Owing to the compact length along the propagation direction in evanescently coupled arrays, large slowing factors of the order of 10^2-10^3 can be achieved even with a weak index contrast of ∼0.1%. The large slowing factor, coupled with weak index contrast, makes this structure a promising candidate for artificial slow light system.
26 citations
TL;DR: Using heterodyne Optical Phase-Locked Loops (OPLLs), two 1W high power 1550 nm master-oscillator-power-amplifier (MOPA) semiconductor lasers operating as current controlled oscillators are phase-locked to a 1 mW reference laser.
Abstract: Using heterodyne Optical Phase-Locked Loops (OPLLs), two 1W high power 1550 nm master-oscillator-power-amplifier (MOPA) semiconductor lasers operating as current controlled oscillators are phase-locked to a 1 mW reference laser. The signals of the two MOPAs are then coherently combined and their mutual coherence is studied. In each OPLL, the acquisition range is increased to +/-1.1GHz with the help of an aided- acquisition circuit. Control of the phase of a single slave MOPA is demonstrated using a RF phase shifter. The differential phase error between two MOPAs locked to the common reference laser is typically 22 degrees.
24 citations
TL;DR: In this article, a comprehensive coupled-mode theory, including resonant vertical emission effects, for the analysis of nonperiodic circular Bragg laser was derived, yielding the threshold gain level and the resonance frequency.
Abstract: We derive a comprehensive coupled-mode theory, including resonant vertical emission effects, for the analysis of nonperiodic circular Bragg lasers. We derive the governing characteristic equation for such lasers, yielding the threshold gain level and the resonance frequency. By reducing the threshold gain and maximizing the ratio of "useful signal" to the power leakage, we find optimum conditions for vertically emitting circular Bragg microdisk lasers which indicate that low-threshold operation is possible
21 citations
TL;DR: This paper proposes and demonstrates effective index-guided, large-area, edge-emitting photonic crystal lasers driven by pulsed electrical current injection at the optical telecommunication wavelength of 1550 nm.
Abstract: Planar broad-area single-mode lasers, with modal widths of the order of tens of microns, are technologically important for high-power applications and improved coupling efficiency into optical fibers. They may also find new areas of applications in on-chip integration with devices that are of similar size scales, such as for spectroscopy in microfluidic chambers or optical signal processing with micro-electromechanical systems. An outstanding challenge is that broad-area lasers often require external means of control, such as injection-locking or a frequency/spatial filter to obtain single-mode operation. In this paper, we propose and demonstrate effective index-guided, large-area, edge-emitting photonic crystal lasers driven by pulsed electrical current injection at the optical telecommunication wavelength of 1550nm. By suitable design of the photonic crystal lattice, our lasers operate in a single mode with a 1/e^2 modal width of 25μm and a length of 600μm.
TL;DR: It is demonstrated that electrically pumped large-area edge-emitting InGaAsP/InP two-dimensional photonic crystal lasers with angled facets at room temperature with fine lasing wavelength tuning sensitivity of 0.08 through the transverse lattice constant tuning.
Abstract: We demonstrate electrically pumped large-area edge-emitting InGaAsP/InP two-dimensional photonic crystal lasers with angled facets at room temperature. The laser uses a weak index perturbation surface photonic crystal structure to control optical modes in the wafer plane. Measurements of the laser spectra show that the modal selection is due to satisfying the Bragg resonance conditions in both the longitudinal and the transverse directions. The lasing wavelength is tuned lithographically by changing photonic crystal lattice constants. We demonstrate a fine lasing wavelength tuning sensitivity (change of lasing wavelength over change of lattice constant) of 0.08 through the transverse lattice constant tuning.
TL;DR: It is numerically demonstrated that, it's possible to get a large-area, high-efficiency, single defect mode lasing in ABR lasers if the authors choose the kind without a pi/2 phase shift in the outer grating and also a device size smaller than a critical value.
Abstract: The modal properties, including the resonant vertical radiation, of a type of laser structures based on the annular Bragg resonance (ABR) are studied in detail. The modal threshold gains and the resonance frequencies of such lasers are obtained from the derived governing characteristic equation. Two kinds of ABR lasers, one with a π/2 phase shift in the outer grating and the other without, are analyzed. It is numerically demonstrated that, it’s possible to get a large-area, high-efficiency, single defect mode lasing in ABR lasers if we choose the kind without a π/2 phase shift in the outer grating and also a device size smaller than a critical value.
TL;DR: In this paper, active, electrically pumped coupled-resonator optical waveguides (CROWs) in the form of InP-InGaAsP Fabry-Perot resonator arrays are investigated.
Abstract: We investigate active, electrically pumped coupled-resonator optical waveguides (CROWs) in the form of InP-InGaAsP Fabry-Perot resonator arrays. We discuss the fabrication of these devices and present measurements of the transmission spectra. The signal-to-noise ratio is found to be a strong function of wavelength and degraded rapidly along the resonator chain away from the input. Our results highlight a number of ingredients toward practical implementations loss-compensated and amplifying CROWs.
TL;DR: Side-coupled standing-wave cavity structures consisting of Fabry-Perot and photonic crystal resonators coupled to two waveguides are analyzed and it is shown that optical bright and dark states, analogous to those observed in coherent light-matter interactions, can exist in these systems.
Abstract: We analyze side-coupled standing-wave cavity structures consisting of Fabry-Perot and photonic crystal resonators coupled to two waveguides. We show that optical bright and dark states, analogous to those observed in coherent light-matter interactions, can exist in these systems. These structures may be useful for variable, switchable delay lines.
TL;DR: In this article, an electrically pumped, singlemode, large-area, edge-emitting InGaAsP/InP two dimensional photonic crystal Bragg laser operating in continuous-wave condition was demonstrated.
Abstract: The authors demonstrate an electrically pumped, single-mode, large-area, edge-emitting InGaAsP/InP two dimensional photonic crystal Bragg laser operating in continuous-wave condition. The laser uses a weak index perturbed, polymer-planarized, surface photonic crystal structure to control the optical mode in the wafer plane. They find that the laser operates in single transverse and longitudinal modes. They compare the performance of the photonic crystal Bragg laser with a broad-area laser fabricated from the same wafer and the comparison shows that the performance penalty incurred by the photonic crystal is small.
TL;DR: Employing design principles, a large-area, edge-emitting, and single-mode semiconductor photonic crystal Bragg laser is experimentally demonstrated with a single-lobed, diffraction-limited far field under continuous wave condition.
Abstract: We investigate the modal losses and field distributions of different order transverse modes supported by the photonic crystal Bragg structure using a transfer matrix method. We find that only the fundamental transverse mode has a single-lobed near field and far field and there exists a trade-off between ensuring lasing in the fundamental transverse mode and reducing the threshold. Employing these design principles, we experimentally demonstrate a large-area, edge-emitting, and single-mode semiconductor photonic crystal Bragg laser with a single-lobed, diffraction-limited far field under continuous wave condition.
06 May 2007
TL;DR: In this paper, the authors demonstrate nanoscale patterning and overlay of two-dimensional gratings and waveguides with accuracy better than 45 nm using electron-beam lithography for surface structure lasers with large areas.
Abstract: We demonstrate nanoscale patterning and overlay of two-dimensional gratings and waveguides with accuracy better than 45 nm using electron-beam lithography for surface structure lasers with large areas.
05 Nov 2007
TL;DR: In this article, two high power semiconductor lasers are phase-locked to a low power master laser using optical phase-lock loops, and a stable power combination efficiency of 95% is achieved using the VCO scheme.
Abstract: Two high power semiconductor lasers are phase-locked to a low power master laser using optical phase-lock loops. Coherent power combination and individual phase control of the SCLs with an RF phase shifter and voltage controlled oscillator are demonstrated. A stable power combination efficiency of 95% is achieved using the VCO scheme.
TL;DR: In this paper, the mid-air oscillations of a party balloon, which occur once its buoyancy is no longer capable of keeping it against the ceiling, are explained in terms of variable-mass dynamics.
Abstract: The intriguing midair oscillations of a party balloon, which occur once its buoyancy is no longer capable of keeping it against the ceiling, is shown to require a rather sophisticated explanation in terms of variable-mass dynamics. The ubiquity of this phenomenon, the accessibility of its actual observation, and the subtlety of its analytic description provide a good opportunity for an interesting zero-cost classroom demonstration.
06 May 2007
TL;DR: In this article, the authors proposed and demonstrated electrically pumped, edge-emitting, large area photonic crystal lasers with index-guided and Bragg-guided lasing modes.
Abstract: We propose and demonstrate electrically pumped, edge-emitting, large-area photonic crystal lasers. Effective index-guided and Bragg-guided lasing modes are obtained depending on the design of photonic crystal and facets.
08 Jul 2007
TL;DR: In this article, active and passive Coupled-Resonator Optical Waveguides (CROWs) are discussed and gain enhancement, noise, and tunability of inactive CROWs and its relation to slowlight.
Abstract: Our on going work on active and passive Coupled-Resonator Optical Waveguides (CROWs) will be presented. I will discuss gain enhancement, noise, and tunability inactive CROWs and its relation to slowlight.
TL;DR: In this article, an electrically-pumped, edge-emitting, single-mode, large-area photonic crystal laser with angled facets was demonstrated. And the spectral and spatial modal control of the laser was obtained by designing the photonic lattice and index contrast.
Abstract: We demonstrate electrically-pumped, edge-emitting, single-mode, large-area photonic crystal lasers with angled facets. We obtain the spectral and spatial modal control of the laser by designing the photonic crystal lattice and index contrast.
16 Sep 2007
TL;DR: In this article, a 1W semiconductor MOPA is locked to a -3dBm reference laser and its 20dB linewidth is reduced from 2.2MHz to 0.22MHz.
Abstract: Using an Optical Phase Lock Loop, a 1W semiconductor MOPA is locked to a -3dBm reference laser and its 20dB linewidth is reduced from 2.2MHz to 0.22MHz.