Codirectionally coupled twin-guide laser diode for broadband electronic wavelength tuning

A novel broadband tunable laser diode is presented. It is based on a codirectional coupling scheme which is predicted to yield tuning ranges larger than 50 nm. Only a single control current is required for tuning. Preliminary devices have been realised indicating a wavelength tuning over 30 nm.<>     

A tunable distributed amplification DFB laser diode (TDA-DFB-LD)

A novel wavelength-tunable distributed amplification distributed feedback laser diode (TDA-DFB-LD) is proposed and fabricated. The proposed structure provides synchronous change between the longitudinal mode and the Bragg wavelength in tuning; thereby continuous wavelength tuning can be realized with single control-current. Moreover, extended tuning is also possible with two control-currents. A continuous tuning range of 2.9 nm and an extended discrete tuning range of 15 nm are experimentally obtained with a 1.55-μm TDA-DFB-LD     

Proposal of electrically tunable external-cavity laser diode

We propose and demonstrate a novel tunable external-cavity laser diode that simultaneously achieves rapid tuning rate and wide tuning range by electrical control. This contains new-type integrated laser diode, collimating lens, and diffraction grating mirror. The integrated laser diode consists of Fabry-Pe/spl acute/rot laser diode and waveguide-type deflector, which can deflect the beam passing through the waveguide. By control of the current in the deflector region, maximum wavelength variation of 8.6 nm and sidemode suppression ratio of >35 dB were obtained.     

一种分布反馈注入放大半导体激光器的研制

研制了一种小型大功率半导体激光器系统。将分布反馈半导体激光器输出的小功率光注入到锥形芯片放大器后实现功率放大,得到功率大于700 mW,波长连续可调谐范围大于1 nm的输出激光。该激光器系统不但结构紧凑、输出功率稳定,而且操作方便。该系统可在激光冷却与囚禁、超冷量子气体、量子信息、原子频标及相关空间实验研究中得到应用。     

Widely tunable Ce- and Er-codoped fluorozirconate fiber laser with 975-nm laser diode pumping

A spectrally narrowed widely tunable Ce/sup 3+/: Er/sup 3+/-codoped fluorozirconate (ZBLAN) fiber laser with a continuous-wave laser diode pumping at 975-nm pumping is demonstrated. Wide tunable range over 120 nm (1490-1610 nm) is attained by using a diffraction grating combined with a tuning mirror in the Ce/sup 3+/: Er/sup 3+/-ZBLAN fiber laser cavity. Rate-equation model analysis shows that the tunable range can expand further by using a wavelength-dependent reflectivity cavity mirror.     

Vertically integrated Mach-Zehnder interferometer (VMZ) widelytunable laser diode with improved wavelength access

A widely tunable laser diode has been developed in InGaAsP/InP at 1.55 μm wavelength using an integrated vertical Mach-Zehnder (VMZ) interferometer. Regular tuning behaviour is obtained with only one wavelength control current over a tuning range of 30 nm with ~50 accessible wavelengths     

Broad-band tunable two-section laser diode with external gratingfeedback

A tunable laser light source consisting of a two-section laser diode and an external grating is discussed. A wide tunable range of 154 nm was realized by improving the antireflection (AR) coating and the coupling efficiency. At both edges of the tunable range, however, the tuning characteristics were strongly influenced by the internal mode, in spite of the high-quality AR coating. The effects of the internal mode were avoided by using a phase-control section of the laser. Consequently, single-mode oscillation can be obtained at any desirable wavelength within the above tunable range by controlling the current injected into the phase-control section     

Continuously wavelength-tunable MQW fabry-perot laser diode pulse source with a fiber-based external cavity

A simple continuously wavelength-tunable fiber ring laser pulse source is demonstrated. Such a source employs a gain-switched multiple quantum-well Fabry-Perot laser diode in a self-seeding scheme and the output pulse wavelength can be tuned continuously via a tunable optical filter. The optical pulses generated exhibit a pulsewidth of 92 ps at the frequency of 2.6 GHz. Within a wide wavelength tuning range of 46 nm, the side-mode suppression ratio and the average power of the output optical pulses obtained are higher than 50.1 dB and 3.3 dBm, respectively, and the pulse spectral stability can be maintained in the whole wavelength tuning range.     

Design and analysis of widely tunable sampled grating DFB laser diode integrated with sampled grating distributed Bragg reflector

A new widely tunable laser diode structure that requires only two tuning currents is proposed. The laser diode consists of a sampled grating distributed feedback (SGDFB) laser diode monolithically integrated with a sampled grating distributed Bragg reflector (SGDBR). The phase control sections are properly inserted between the grating bursts of the SGDBR and SGDFB sections for the discrete and continuous tuning. To confirm the feasibility of the new structure, the split-step time domain model is used. The simulation result for a particular design shows that the tuning range as wide as 27 nm is possible with side-mode suppression ratio exceeding 35 dB. Furthermore, the output power is larger than that from SGDBR laser diodes with similar parameters.     

Electroabsorption modulator-integrated distributed Bragg reflector laser diode for C-band WDM-based networks

We report an electroabsorption modulator (EAM)-integrated distributed Bragg reflector laser diode (DBR-LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR-LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue-shift and red-shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR-LD is intensity-modulated through the EAM voltage, which is integrated monolithically with the DBR-LD using a butt–joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn-to-zero and 50 Gb/s pulse amplitude modulation 4-level, respectively.     

紧凑型光栅外腔可调谐半导体激光器

研制了一台结构紧凑的窄线宽、可调谐半导体激光器.采用光栅外腔Littrow结构,将光栅和平面反射镜置于同一个旋转平台上,并使光栅衍射平面和平面镜反射平面的交线与平台旋转轴重合,通过旋转平台实现光栅外腔选取单纵模、压窄线宽和波长调谐,并保证输出光的方位不发生改变,同时用棱镜将输出光斑压缩成为类方形.该激光器的尺寸为110 mm×80 mm×35 mm,中心输出波长为653 nm,谱宽0.07 nm,调谐范围4.6 nm,可连续稳定运转4小时以上.     

半导体激光器生成双波长超窄脉冲的实验研究

描述了一种用腔外注入方式调制增益的法布里珀罗半导体激光器产生双波长超窄脉冲的简单方法，腔外注入功能部分包含一个直流工作的法面里珀罗半导体激光器，一个3dB光耦合器和两个布喇格型光纤光栅。双波长的选择和间距通过调节光栅为实现，文中描述的系统实现了在10nm的调节范围内边模压制率优于17dB的理想结果。整个系统简单、成本低。     

Design and realization of a buried-heterostructuretunable-twin-guide laser diode with electrical blocking regions

An InGaAsP-InP buried-heterostructure tunable-twin-guide (TTG) laser diode is presented, incorporating epitaxially regrown p-n-p-n current blocking regions to minimize current leakage around the active region in the ridge. The laser design is based on a theoretical model describing the mechanism of current leakage and the influence of electrical blocking regions by a two-dimensional computer simulation. The technological realization of the laser device reveals a way to achieve a self-aligned transverse blocking region and a lateral ridge contact in any desired depth by a two-stage epitaxial process. Completely processed TTG laser diodes with buried blocking regions exhibit very good high-temperature performance and a wavelength tuning range of around 4.5 nm under forward bias together with a maximum light output of as much as 25 mW at room temperature     

调谐二极管激光吸收光谱技术中的线形误差与校正

在调谐二极管激光吸收光谱(TDLAS)技术中,谱线线形的检测精度受激光器调谐非线性和调制幅度的影响,本文针对近红外分布反馈(DFB)激光器,通过激光器的调谐特性曲线定量分析了调谐非线性和调制幅度对吸收线形的影响,提出了调谐非线性校正和调制幅度补偿方法,并通过实验验证了方法的有效性.实验结果表明,调谐非线性校正可以提高谱...     

Continuously tunable metal-clad ridge-waveguide distributed feedback laser diode (InGaAsP-InP)

The tunable twin-guide (TTG) structure has been realised with the metal-clad ridge-waveguide (MCRW) distributed feedback (DFB) laser yielding continuous tuning up to 2 nm, output power above 10 mW and linewidth below 10 MHz. The relatively simple fabrication technology and high reliability make this device well suited as a tunable light source for advanced optical communication systems.<>     

Optimized operation of self-seeded gain-switched laser diode forelectrically wavelength-tunable singlemode pulses

A gain-switched Fabry-Perot laser diode at 1.3 μm was self-seeded at different electrical bias and optical feedback rates. With a strong feedback, a comparatively large tuning range and a high sidemode suppression ratio were obtained but multimode emission might occur around the center of the range. Similar phenomenon was observed at a weaker feedback when the electrical bias was sufficiently large. The degradation in tunability was attributed to a broadening of the optical pulses, resulting in temporal overlapping of different longitudinal modes. Our optimized feedback of 2.5% and 3.1 mA bias provided a tuning range of 23.5 nm with a sidemode suppression ratio >10 dB     

可调谐单频掺镱光纤DBR激光器

对分布布拉格反射(DBR)的透射特性进行了分析,制作了一个单频窄线宽掺镱光纤DBR激光器.在977 nm半导体激光器泵浦下,在1052.5 nm波长处输出功率可达4 mW,线宽小于8 MHz(受测量仪器分辨率限制).采用弧形梁调谐光纤光栅,实现了DBR光纤激光器在单纵模工作状态下的连续调谐,调谐范围可达20.4 nm(1036.1～1056.5 nm),并研究了调谐对激光器的泵浦阈值和斜率效率的影响.     

Multiwavelength 10-GHz picosecond pulse generation from asingle-stripe semiconductor diode laser

A single-stripe GaAs-AlGaAs semiconductor optical amplifier (SOA) has been used to generate four tunable wavelength-division multiplexed (WDM) channels simultaneously, each transmitting 12-ps pulses at 2.5 GHz, for an aggregate pulse rate of 10 GHz. Wavelength tuning over 18 nm has been demonstrated with channel spacing ranging from 0.8 to 2.1 nm. A potential spectral correlation across the multiwavelength spectrum has been studied in both experiment and simulation methods. These results show the potential for utilizing single stripe laser diodes as multiwavelength sources in WDM-TDM network     

Single-mode operation characteristics of a self-injection seededFabry-Perot laser diode with distributed feedback from a fiber grating

We study the operational characteristics of a self-injection seeded laser diode in an external cavity consisting of a fiber Bragg grating. The distributed feedback (DFB) of light in the grating provides an additional tolerance of frequency detuning in mode selection. The spectral characteristics at different operating frequencies and feedback rates have been investigated. Wavelength tuning has also been realized by applying compressive and tensile strain to the grating and a tuning range of 11.6 nm has been obtained     

A widely tunable erbium-doped fiber laser pumped at 532 nm

A tunable erbium-doped fiber laser with a very wide continuous-tuning range (1522-1567 nm) is discussed. The wide tuning range was achieved using an aluminum/erbium-doped fiber; the aluminum codoping is known to broaden the gain spectrum substantially. The tunable fiber laser has a ring laser configuration utilizing an inline tunable etalon as the tuning element. Continuous tuning over 45 nm in the spectral range of 1522-1567 nm was achieved with 80 nW of pumping at 532 nm, using the second harmonic of a Nd:YAG laser as the pump source