An Integratable Distributed Bragg Reflector Laser by Low-Energy Ion Implantation Induced Quantum Well Intermixing

An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.

Quantum Well Intermixing of InGaAsP QWs by Impurity Free Vacancy Diffusion Using SiO_2 Encapsulation

Experiment on quantum well intermixing (QWI) of InGaAsP QWs by impurity free vacancy diffusion (IFVD) using SiO 2 encapsulation is reported.A maximum band gap wavelength blue shift as large as 200nm is realized.Furthermore,an FP laser blue shifted 21nm by QWI is fabricated with characteristics comparable with the as grown one.

Research on quantum well intermixing of 680 nm AlGaInP/GaInP semiconductor lasers induced by composited Si-Si_(3)N_(4) dielectric layer

The optical catastrophic damage that usually occurs at the cavity surface of semiconductor lasers has become the main bottleneck affecting the improvement of laser output power and long-term reliability.To improve the output power of 680 nm AlGaInP/GaInP quantum well red semiconductor lasers,Si-Si_(3)N_(4)composited dielectric layers are used to induce its quantum wells to be intermixed at the cavity surface to make a non-absorption window.Si with a thickness of 100 nm and Si_(3)N_(4)with a thickness of 100 nm were grown on the surface of the epitaxial wafer by magnetron sputtering and PECVD as diffusion source and driving source,respectively.Compared with traditional Si impurity induced quantum well intermixing,this paper realizes the blue shift of 54.8 nm in the nonabsorbent window region at a lower annealing temperature of 600 ℃ and annealing time of 10 min.Under this annealing condition,the wavelength of the gain luminescence region basically does not shift to short wavelength,and the surface morphology of the whole epitaxial wafer remains fine after annealing.The application of this process condition can reduce the difficulty of production and save cost,which provides an effective method for upcoming fabrication.

Plasma-enhanced Chemical Vapordeposition SiO_2 Film after Ion Implantation Induces Quantum Well Intermixing

A method of QWI （ quantum well intermixing） realizing through plasma-enhanced chemical vapordepositiom （PECVD） SiO2 film following ion implantation was investigated. PECVD 200 mn SiO2 film after 160 keV phosphorus（P） ion implantation was performed to induce InP-based multiple-quantum-well （MQW） laser structural intermixing, annealing process was carried out at 780 ℃ for 30 seconds under N2 flue, the blue shift ofphotoluminescenee （PL） peak related to implanted dose ： 1 × 10^11, 1 × 10^12, 1×10^13 ,3 × 10^13 , 7× 10^13 ion/ cm^2 is 22 nm, 65 nm, 104 nm, 109 nm, 101 nm, respectively. Under the same conditions, by comparing the blue shift of PL peak with P ion implantation only, slight differentiation between the two methods was observed, and results reveal that the defects in the implanting layers generated by ion implantation are much more than those in SiO2 film. So, the blue shift results mainly from ion implantation. However, SiO2 film also may promote the quantum well intermixing.

InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation

A quantum well intermixing（QW1） investigation on double quantum well（DQW） structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing （RTA） was carried out by means of photoluminescence（PL）. The ion implantation was performed at the energy of 120 keV with the dose ranging from 1 × 10^11cm^-2 to 1× 10^14cm^-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation（-1 × 10^11cm^-2） indicating that the implant vacancy distribution affects the QWl. When the ion dose is over - 1 × 10^12cm^-2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.

Monolithic integration of electroabsorption modulators and tunnel injection distributed feedback lasers using quantum well intermixing

Electroabsorption modulators combining Franz-Keldysh effect and quantum confined Stark effect have been mono-lithically integrated with tunnel-injection quantum-well distributed feedback lasers using a quantum well intermixing method. Superior characteristics such as extinction ratio and temperature insensitivity have been demonstrated at wide temperature ranges.

Wavelength Tuning in Two-Section Distributed Bragg Reflector Laser by Selective Intermixing of InGaAsP-InGaAsP Quantum Well Structure

The two-section tunable ridge waveguide distribu ted Bragg reflector (DBR) laser fabricated by the selective intermixing of an InGaAsP-InGaAsP quantum well structure is presented.The threshold current of the laser is 51mA.The tunable range of the laser is 4.6nm,and the side mode suppress ion ratio (SMSR) is 40dB.

Study of quantum well mixing induced by impurity-free vacancy in the primary epitaxial wafers of a 915 nm semiconductor laser

Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the further improvement of the output power and affect the reliability.To improve the anti-optical disaster ability of the cavity surface,a non-absorption window(NAW)is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mix-ing(QWI)induced by impurity-free vacancy.Both the principle and the process of point defect diffusion are described in detail in this paper.We also studied the effects of annealing temperature,annealing time,and the thickness of SiO_(2) film on the quan-tum well mixing in a semiconductor laser with a primary epitaxial structure,which is distinct from the previous structures.We found that when compared with the complete epitaxial structure,the blue shift of the semiconductor laser with the primary epi-taxial structure is larger under the same conditions.To obtain the appropriate blue shift window,the primary epitaxial struc-ture can use a lower annealing temperature and shorter annealing time.In addition,the process is less expensive.We also pro-vide references for upcoming device fabrication.

Spatial control based quantum well intermixing in InP/InGaAsP structures using ICP

This paper presents a new method based on spatial controlling in quantum well intermixing in InP/InGaAsP structures using ICP technology.The degree of bandgap energy shift in the same wafer can be controlled flexibly using masks with different duty ratios.With an optimal condition including ICP-RIE etching depth, SiO_2 deposition,and RTA process,five different degrees of blue-shift with maximum of 75 nm were obtained in the same sample.The result shows that our method is an effective way to fabricate monolithic integration devices, especially in multi-bandgap structures.

An Electroabsorption Modulator Monolithically Integrated with a Semiconductor Optical Amplifier and a Dual-Waveguide Spot-Size Converter

A semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a spotsize converter input and output is fabricated by means of selective area growth,quantum well intermixing,and asymmetric twin waveguide technology. A 1550-1600nm lossless operation with a high DC extinction ratio of 25dB and more than 10GHz 3dB bandwidth are successfully achieved. The output beam divergence angles of the device in the horizontal and vertical directions are as small as 7.3°× 18.0°, respectively, resulting in a 3.0dB coupling loss with a cleaved single-mode optical fiber.

Dual-wavelength distributed Bragg reflector semiconductor laser based on a composite resonant cavity

We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.

High-performance electroabsorption modulator

A 100-μm-long electroabsorption modulator monolithically integrated with passive waveguides at the input and output ports is fabricated through ion implantation induced quantum well intermixing, using only a twostep low-pressure metal-organic vapor phase epitaxial process. An InGaAsP/InGaAsP intra-step quantum well is introduced to the active region to improve the modulation properties. In the experiment high modulation speed and high extinction ratio are obtained simultaneously, the electrical-to-optical frequency response （E/O response） without any load termination reaches to 22 GHz, and extinction ration is as high as 16 dB.