Epitaxially grown quantum dot (QD) lasers are emerging as an economical approach to obtain on-chip light sources. Thanks the three-dimensional confinement of carriers, QDs show greatly improved tolerance defects and promise other advantages such low transparency current density, high temperature operation, isolator-free enhanced four-wave-mixing. These material properties distinguish them from traditional III–V/Si wells (QWs) have spawned intense interest explore a full set photonic...

Free-space laser communications offer a promising alternative for broadband data transmission in places where fiber optics are impractical. This technology, particularly effective at the 1.55 μm wavelength near infrared, also has potential applications medium-wave infrared (MWIR, 3–5 μm) and long-wave (LWIR, 8–14 ranges. MWIR LWIR superior through fog, clouds, dust, with offering stealth advantages thanks to natural thermal radiation. In addition, mid-infrared wavelengths benefit from...

Optical transmission of a two-dimensional array subwavelength holes in metal film has been numerically studied using differential method. Transmission spectra have calculated showing significant increase the certain spectral ranges corresponding to excitation surface polariton Bloch waves on with periodic hole structure. Under enhanced conditions, near-field distribution transmitted light reveals an intensity enhancement greater than 2 orders magnitude localized ( approximately 40 nm) spots...

This letter reports on a 1.3-μm reflection insensitive transmission with quantum dot laser directly grown silicon in the presence of strong optical feedback. These results show penalty-free at 10 GHz under external modulation -7.4-dB The feedback insensitivity from low linewidth enhancement factor, high damping, absence off-resonance emission states, and shorter carrier lifetime. paves way for future chip high-speed integrated circuits operating without isolators.

Mid-infrared free-space optical communication has a large potential for high speed due to its immunity electromagnetic interference. However, data security against eavesdroppers is among the obstacles private communication. Here, we show that two uni-directionally coupled quantum cascade lasers operating in chaotic regime and synchronization between them allow extraction of information been camouflaged emission. This building block represents key tool implement degree privacy directly on...

This study deals with the communication capabilities of two kinds semiconductor lasers emitting in one atmosphere transparency windows, around 4 μm. One these is a quantum cascade laser and other an interband laser. With laser, subsequent attenuation added to optical path order mimic free-space transmission several kilometers. Direct electrical modulation used transmit message two-level formats, non-return-to-zero return-to-zero, are compared terms maximum data rate. The sensitivity feedback...

Space-to-ground high-speed transmission is of utmost importance for the development a worldwide broadband network. Mid-infrared wavelengths offer numerous advantages building such system, spanning from low atmospheric attenuation to eye-safe operation and resistance inclement weather conditions. We demonstrate full interband cascade system around wavelength 4.18 µm. The low-power consumption both laser detector in combination with large modulation bandwidth sufficient output power makes this...

Chaos in nonlinear dynamical systems is featured with irregular appearance and high sensitivity to initial conditions. Near-infrared light chaos based on semiconductor lasers has been extensively studied enabled various applications. Here, we report a fully-developed hyperchaos the mid-infrared regime, which produced from interband cascade subject external optical feedback. Lyapunov spectrum analysis demonstrates that exhibits three positive exponents. Particularly, chaotic signal covers...

Stable laser emission with narrow linewidth is of critical importance in many applications, including coherent communications, LIDAR, and remote sensing. In this work, the physics underlying spectral narrowing self-injection-locked on-chip lasers to Hz-level lasing investigated using a composite-cavity structure. Heterogeneously integrated III-V/SiN operating quantum-dot quantum-well active regions are analyzed focus on effects carrier quantum confinement. The intrinsic differences...

Silicon-on-insulator (SOI) optical waveguides with high electromagnetic field confinement suffer from sidewall roughness which is responsible for strong scattering effects. This letter reports a numerical investigation on the size influence of ultrasmall SOI propagation loss due to roughness. It shown that smaller than 260 /spl times/ nm roughness-induced decreases. As mode reduced, very low light coupling and single-mode fiber can be achieved as 0.5 dB/cm 150 cross-sectional waveguide.

This work reports on the ultra-low linewidth enhancement factor (αH-factor) of semiconductor quantum dot lasers epitaxially grown silicon. Owing to low density threading dislocations and resultant high gain, an αH value 0.13 that is rather independent temperature range (288 K–308 K) measured. Above laser threshold, does not increase extensively with bias current which very promising for realization future integrated circuits including performance sources.

Abstract The onset of nonlinear dynamics and chaos is evidenced in a mid-infrared distributed feedback quantum cascade laser both the temporal frequency domains. As opposed to commonly observed route semiconductor lasers, which involves undamping relaxation oscillations, lasers first exhibit regular self-pulsation at external cavity before entering into chaotic low-frequency fluctuation regime. bifurcation sequence, similar that already class A gas under optical feedback, results from fast...

This work reports on a systematic investigation of the influence optical feedback in InAs/GaAs quantum dot lasers epitaxially grown silicon. The boundaries associated to onset critical level corresponding first Hopf bifurcation are extracted at different bias conditions with respect excited state transition. Overall, results show that directly onto silicon much more resistant than well lasers, mostly resulting from small linewidth enhancement factor high-quality material. However, also...

Abstract Free space optics data transmission with bitrate in excess of 10 Gbit s −1 is demonstrated at 9 µm wavelength by using a unipolar quantum optoelectronic system room temperature, composed cascade laser, modulator, and detector. The large frequency bandwidth the set detector modulator that are both high devices, while laser emits continuous wave. amplitude relies on Stark shift an absorbing optical transition out frequency. This device designed to avoid charge displacement, therefore...

Abstract Photonic integrated circuits (PICs) have enabled numerous high performance, energy efficient, and compact technologies for optical communications, sensing, metrology. One of the biggest challenges in scaling PICs comes from parasitic reflections that feed light back into laser source. These increase noise may cause destabilization. To avoid reflections, expensive bulky isolators been placed between rest PIC leading to large increases device footprint on-chip integration schemes...

In environments where traditional fiber optic cables are impractical, free-space optical communications offer a promising solution for transmitting large amounts of data, especially in the mid-infrared wavelength range. Despite advantages minimal atmospheric interference and stable signals, vulnerability wireless to eavesdropping poses significant challenge. This study addresses this challenge by demonstrating method privately data using photonic chaos from distributed feedback quantum...

Silicon-on-insulator (SOI) optical waveguides insure high electromagnetic field confinement but suffer both from sidewall roughness responsible of scattering effects and leakage toward the silicon substrate. These two mechanisms are main sources loss in such waveguides. Considering case single-mode ultrasmall square SOI waveguides, propagation is calculated at telecommunication wavelengths taking into account these contributions. Leakage substrate strongly depend on waveguide size as well...

In this paper, a technique based on the use of Mach-Zehnder (MZ) interferometer is proposed to evaluate chirp properties, as well linewidth enhancement factor ( <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">αH</sub> -factor) optoelectronic devices. When device modulated, experimental setup allows extraction component's response amplitude modulation (AM) and frequency (FM) that can be used obtain value -factor. As compared with other...

This paper reports on the spectral linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion factor and enhancement factor, narrow 160 kHz (80 intrinsic linewidth) with sensitivity temperature is demonstrated. When using anti-reflection coatings both facets, operation extended high powers, believed be due reduction in longitudinal spatial hole burning. These results confirm potential lasers for increasing transmission capacity future coherent communication systems.

The modulation dynamics and the linewidth enhancement factor of excited-state (ES) lasing quantum dot (QD) semiconductor lasers are investigated through a set improved rate equation model, in which contribution off-resonant states to refractive index change is taken into account. ES laser exhibits broader response associated with much lower chirp-to-power ratio comparison ground-state (GS) laser. In addition, it found that emission reduces QD by about 40% than GS. These properties make...

We present an experimental investigation on the period-one dynamics of optically injected InAs/GaAs quantum dot laser as a photonic microwave source. It is shown that frequency laser's oscillation continuously tunable through adjustment detuning. The power enhanced by increasing injection strength providing operation away from Hopf bifurcation, whereas second-harmonic distortion electrical signal well reduced detuning frequency. Both strong optical and high are favorable for obtaining single...

This work investigates the performance of 1.3-μm quantum dot lasers epitaxially grown on silicon under optical feedback sensitivity with different temperature and doping profiles. Experiments show that these exhibit a very high degree resistance to both incoherent coherent feedbacks. 10 Gbps penalty-free transmissions are also unveiled external modulation at temperatures. The paper draws attention p-doping better thermal resistance, lower linewidth enhancement factor, higher critical level,...

Free-space optical communication is a very promising alternative to fiber systems, in terms of ease deployment and costs. Midinfrared light has several features utter relevance for free-space applications: low absorption when propagating the atmosphere even under adverse conditions, robustness wavefront during long-distance propagation, absence regulations restrictions this range wavelengths. A proof-of-concept high-speed transmission taking advantage intersubband devices recently been...

Using the conventional rate equations describing an injection-locked system, a novel modulation response function is derived, which implicitly incorporates nonlinear gain through free-running relaxation oscillation frequency and damping of slave laser. In this paper, it shown that model presented can be used to extract characteristic parameters coupled system from experimental data. The number fitting in reduced by determining fundamental function; these are considered constant during...