双波长可调外腔半导体激光器

提出了一种基于体布拉格光栅（VBG）和横向啁啾体布拉格光栅（TCVBG）组合的双光栅外腔半导体激光器,该外腔半导体激光器采用反射率15%的体光栅和反射率17%的啁啾体布拉格光栅作为反馈元件和模式选择元件,实现特定波长的选择和调谐,实验研究了外腔激光器的功率-电流特性、光谱特性和波长调谐特性。实验结果表明:双光栅外腔半导体激光器最大输出功率为1.96 W,斜率效率为0.94 W/A,外腔效率达到78%。输出光谱为双波长,一个波长为808.6 nm,另一个波长连续可调,通过改变横向啁啾体光栅的位置,该波长可从800 nm调谐至815 nm,可调范围达15 nm,在整个可调范围内两个波长的谱线宽度（FWHM）均小于0.3 nm。     

高功率激光二极管抽运Nd:YAG连续双波长激光器

通过双波长理论计算确定了双波长运转时腔镜介质膜在不同波长的最佳透射率以及激光腔内不同波长的衍射损耗，最终利用四腔镜双谐振腔结构实现了激光二极管（LD）侧面抽运Nd：YAG激光器在1064nm和1319nm的双波长同时连续运转，并分析了激光腔长与双波长激光输出功率比值之间的关系以及抑制1338nm等其他波长运转的方法。在抽运功率为500W时，实现了平均功率超过45W的连续激光输出，1064nm和1319nm单一波长连续输出功率均超过20W。两波长输出的光束质量因子M^2分别为32和39。输出功率不稳定性均小于5％。     

外腔半导体激光器动态模稳定性的研究

为了研究调谐过程中外腔半导体激光器的模稳定性,采用多光束干涉理论推导Littrow结构外腔半导体激光器的腔增益,并模拟其模结构。分析了光栅面和转臂不在同一平面的情形下,在光栅转动调谐时,通过匹配光栅的反馈波长变化率与外腔波长变化率,推导出最佳的初始外腔长度,并研究了动态模稳定（无跳模调谐）的范围;采用严格的耦合理论和光线变换矩阵分析了准直（耦合）透镜的位置对系统后向耦合效率的影响。结果表明,系统后向耦合效率最大可达99%,极大地压窄了中心波长为780nm半导体激光器的线宽,外腔半导体激光器的理论线宽为未加外腔时的0.96%,动态模稳定范围可达6.8nm。     

采用可调Mach-Zehnder滤波的波长可切换掺铒光纤激光器

为了实现高稳定性的可调谐激光输出,提出并设计了一种基于马赫-曾德（M-Z）结构和光纤光栅串结合的掺铒光纤激光器,在M-Z干涉结构的一个干涉臂中加入光学延迟线（ODL）,实现对干涉间隔的灵活可调。系统结构设计采用976 nm波长的LD作为泵浦源,长度为6 m的掺铒光纤作为增益介质;采用光栅串将特定波长的光反射回环形腔形成振荡;采用M-Z结构产生梳状滤波用来对光栅串反射回的光进行选择;通过调节ODL来改变腔内损耗,进而实现激光的可调谐输出,并通过在系统中加入可饱和吸收体（SA）和子腔结构来抑制波长的跳变。实验中,在泵浦功率为100 mW时,实现了单波长双波长和三波长的稳定的激光输出。单波长共输出13个,调谐范围为1 570~1 596 nm,调谐间隔为2 nm,边模抑制比均大于50 dB。     

外腔式KGd(WO4)2 Raman激光器的输出特性研究

研究了外腔式KGd（WO4）2 Raman激光器在红外纳秒脉冲抽运下的输出特性，通过改变KGd（WO4）2晶体的方位，实验得到了1159nm、1178nm、1272nm和1317nm 4个波长的红外Raman激光输出。波长为1159nm和1178nm的一阶Stokes脉冲的最大输出能量分别为23．9mJ和19．2mJ，相应的转换效率分别为34．8％和28％；波长为1272nm和1317nm的二阶Stokes脉冲的最大输出能量分别为17．6mJ和15．2mJ，相应的转换效率分别为28．1％和22．7％。     

在800~1100nm范围内实现基于狄拉克半金属的多波段超材料波导

提出了一种基于Dirac半金属层的具有四个方孔谐振器的超材料波导,其波长范围为800~1100nm。 在共振波长842nm,921nm,1010nm和1061nm处分别获得四个透射峰（70％,61％,72％和63％）。 这些透射峰源自于分布在主腔和腔1、2、3或4中的磁场的干涉增强作用。通过将费米能量从50meV增加到70meV,可以增加四个透射峰并将其转移到更短的波长。 所提出的超材料波导可能在纳米级滤波器,开关或折射率传感器中应用。     

基于非对称F-P滤波器的光纤光栅解调技术

介绍了利用非对称光纤Fabry-Pérot（F-P）腔作为边沿滤波器的光纤光栅波长移位检测方案。基于薄膜干涉理论对该非对称F?蛳P腔的反射率响应关系进行计算与分析，得出该F-P腔的结构参数，改善了普通F?蛳P腔的反射特性，具有线性范围宽和线性度好的优点。利用该F-P腔的某一线性滤波边缘,将传感光栅的波长信息转化为功率信息进行检测，可完成光纤光栅的传感波长解调。采用该检测方案进行了光纤光栅应变传感实验,实现了在7 nm范围内的波长线性解调,测量波长分辨率为0.01 nm。     

基于MMI滤波器的可调谐连续光全光纤OPO

在连续光全光纤光学参量振荡器（FOPO）中,目前主要利用可调滤波器（TBPF）等高插入损耗的滤波器件进行边带光输出波长的调谐,这种方式所引起的高环形腔损耗限制了FOPO输出性能的进一步提升。为解决此问题,提出了基于多模干涉（MMI）滤波器的低腔损耗可调谐连续光FOPO。通过选取不同长度和纤芯尺寸的多模光纤制作级联单模-多模-单模光纤（SMS）作为滤波器件,使其在选定波长处的插入损耗小于1 dB,FOPO环形腔的总损耗不大于5 dB,并通过对SMS器件施加轴向拉力的方式调节滤波器件的透射谱,实现了1 494~1 501 nm和1 638~1 629 nm范围内的双边带可调谐连续光输出。     

2μm波段混合复合谐振腔型单纵模光纤激光器

设计并演示了一种2μm波段高信噪比混合复合谐振腔型单纵模（SLM）掺铥光纤激光器（TDFL）。混合复合谐振腔由基于3个均匀光纤布拉格光栅（FBG）和2个光纤耦合器（OC）的非对称线形复合四腔和基于另外2个OC的双OC环形腔组成。基于游标原理，非对称线形复合四腔可以实现激光SLM选择。双OC环形腔作为窄带滤波器，进一步确保激光器长时间SLM稳定运行。采用放大的1567 nm激光泵浦掺铥光纤，当泵浦功率为2.80 W时，激光输出中心波长为2049.160 nm，输出功率为15.47 mW，光信噪比高达75.65 dB,200 min测量时间内波长和功率波动分别小于0.005 nm和0.85 dB,10 min测量时间内激光可以保持稳定的SLM运行，激光器的阈值泵浦功率和斜率效率分别为1.75 W和1.43%。提出的TDFL在自由空间光通信、激光雷达、光学传感等领域具有潜在的应用价值。     

VEGAS维纳斯四合一激光器祛除各种错误文饰1174例

目的：观察VEGAS维纳斯四合一激光器（波长1064nm黑色），（波长755nm黄色），（Q开关倍频532nm红色）祛除皮肤文饰的效果和特殊性，探讨各种文饰在治疗中的反应。方法：应用VEGAS维纳斯四合一激光器（波长1064nm黑色），（波长755nm黄色）（Q开关倍频532nm红色）对1174例文眉，文眼线，文身，外伤文身，文唇进行观察治疗。结果：此方法有效率达100%，具有操作简单，痛苦小，组织损伤小，不留瘢痕，恢复快，治愈率高和省时，省力等优点。结论：VEGAS维纳斯四合一激光器（波长1064nm黑色），（波长755nm黄色），（Q开关倍频532nm红色）祛除黑色，红色，深兰色，彩色图案，兰黑色，绿色，黄色效果好。     

一种线形腔的多波长布里渊掺铒光纤激光器

布里渊掺铒光纤激光器(BEFL)是一种利用非线性效应——布里渊散射来实现多波长输出的激光器,波长间隔大约为0.088 nm(11 GHz).研究了一种多波长布里渊掺铒光纤激光器线形结构,通过引入反馈实现多波长输出.在布里渊泵浦功率为11 mW,980 nm泵浦功率为12 mW时获得了波长间隔为0.08 nm的34个波长的激光输出以及1 525～1 570 nm可调谐范围.并通过调节980 nm抽运光功率以及布里渊泵浦光波长,实现了可调谐的多波长输出.还研究了980 nm抽运光功率对产生的斯托克斯光波数的影响.     

Multiwavelength DFB laser array transmitters for ONTCreconfigurable optical network testbed

We discuss the design, fabrication, and performance of experimental multiwavelength laser array transmitters that have been used in the reconfigurable optical network testbed for the Optical Network Technology Consortium (ONTC). The experimental four-node multiwavelength network testbed is SONET/ATM compatible. It has employed multiwavelength DFB laser arrays with 4 nm wavelength spacing for the first time. The testbed has demonstrated that multiwavelength DFB laser arrays are indeed practical and reproducible. For the DFB laser arrays used in such a network the precise wavelength spacing in the array and the absolute wavelength control are the most challenging tasks. We have obtained wavelength accuracy better than ±0.35 nm for all lasers, with some registered to better than ±0.2 nm. We have also studied the array yield of our devices and used wavelength redundancy to improve the array yield. Coupling efficiencies between -2.1 to -4.5 dB for each wavelength channel have been obtained. It is achieved by using specially designed lensed fiber arrays placed on a silicon V-grooved substrate to exactly match the laser spacing. The transmitter consisted of a multichip module containing a DFB laser array, an eight-channel driver array based on GaAs IC's, and associated RF circuitry     

Multiwavelength erbium-doped fiber ring laser employing Fabry–Perot etalon inside cavity operating in room temperature

In this investigation, we propose and demonstrate a simple and cost-effective erbium-doped fiber (EDF) ring laser using a Fabry–Perot etalon inside a linear cavity and employing the accurate fiber cavity length to satisfy the least common multiple number for generating multiwavelength in C-band at room temperature. Furthermore, the center wavelength of the lasing wavelength bands can be adjusted to 1541.02, 1551.32, and 1562.03 nm, respectively. The wavelength separation in each wavelength band is 0.34 nm. Moreover, the output stability of the multiwavelength laser has also been discussed and analyzed.     

Lasing wavelength and spacing switchable multiwavelength fiber laser from 1510 to 1620 nm

We experimentally demonstrate a flexibly switchable multiwavelength fiber laser with multiple functionalities like a wide tuning range of lasing wavelength, wavelength spacing, and the number of channels simultaneously. The lasing wavelength is controlled in the range from 1510 to 1620 nm based on the effect of nonlinear gain compression of a semiconductor optical amplifier incorporated with an erbium-doped fiber amplifier. The wavelength spacing and the number of channels in the multiwavelength fiber laser are readily controlled by the effective length of polarization-maintaining fiber (PMF) segments in the intracavity PMF Lyot-Sagnac filter.     

Tunable multiwavelength fiber ring lasers using a programmable high-birefringence fiber loop mirror

We demonstrate a comb filter with digitally tunable wavelength spacing using a programmable high-birefringence (HiBi) fiber loop mirror (FLM). We then use the HiBi-FLM to implement a tunable multiwavelength semiconductor optical amplifier (SOA)-based fiber ring laser and a tunable multiwavelength all-fiber Raman ring laser. Both lasers exhibit stable room-temperature operation and have a wavelength spacing that is digitally tunable between 1.6 and 3.2 nm. With the SOA-based configuration, we obtain six wavelengths with a spacing of 3.2 nm and 11 wavelengths with a spacing of 1.6 nm; with the all-fiber Raman-based configuration, we obtain four wavelengths with a spacing of 3.2 nm and five wavelengths with a spacing of 1.6 nm.     

Multiwavelength erbium-doped fiber ring laser incorporating an SOA-based phase Modulator

A novel room-temperature multiwavelength erbium-doped fiber (EDF) laser is demonstrated. Stable multiwavelength lasing at room temperature is realized by incorporating a semiconductor optical amplifier (SOA)-based phase modulator in the laser cavity. The SOA is biased below the transparent point with a sinusoidal signal applied to achieve phase modulation, to suppress the homogenous line broadening of the EDF. Stable multiwavelength lasing with wavelengths up to 26 and wavelength spacing as small as 0.19 nm is demonstrated at room temperature.     

Simple multiwavelength device fabrication technique using a single-grating holographic exposure

A simple technique, using a single-grating holographic exposure associated with localized selective etching steps, has been developed for multiwavelength device fabrication. Four-wavelength DBR laser arrays with a 5 nm Bragg wavelength spacing have been fabricated for wavelength division multiplexing (WDM) applications with this method. These devices exhibit uniformly low-threshold currents (10-15 mA), high-output powers (15 mW) and wide tunabilities (12 nm), leading to an overall accessible wavelength domain of 28 nm for the array.     

A self-seeded tunable multiwavelength erbium-doped fiber ring laser with fiber bending scheme

A new tunable multiwavelength fiber laser is proposed. Such a laser contains a homogeneous and inhomogeneous broadening media, i.e., a Fabry–Perót laser diode and an erbium-doped fiber amplifier, in the laser cavity. The Fabry–Perót laser diode is used to obtain tunable multiwavelength lasing. By adjusting the injection current of the Fabry–Perót laser diode, emission at a single wavelength, dual wavelengths, triple wavelengths or quadruple wavelengths are obtained. The lasing wavelength is tuned by bending a section of fiber in the laser cavity. The tuning ranges for single wavelength lasing and dual wavelength lasing are 20 nm and 10 nm, respectively, while those for triple wavelength lasing and quadruple wavelength lasing are 7 nm and 3 nm, respectively.     

Multiwavelength pulse generation using an actively mode-locked erbium-doped fiber ring laser based on distributed dispersion cavity

A simple design of a stable multiwavelength pulse generator was demonstrated using a dispersion-tuned actively mode-locked erbium-doped fiber (EDF) ring laser with distributed dispersion cavity. The distributed dispersion cavity in the fiber laser successfully reduced the cross-gain saturation in EDF, and thus, enabled multiwavelength operation. Simultaneous generation of wavelength-tunable 10-GHz pulses up to four different wavelengths was achieved with the same wavelength space of 2.94 nm. The extinction ratio of all wavelengths was above 30 dB. In addition, smooth wavelength tuning was achieved over more than 41 nm when the laser was working at dual-wavelength mode. The super mode noise was /spl sim/60 dB below the signal level at both wavelengths. The laser state was found to be very stable.     

Investigation of room-temperature multiwavelength fiber-ring laser that incorporates an SOA-based phase modulator in the laser cavity

A theoretical and experimental study of a multiwavelength fiber-ring laser that incorporates a semiconductor optical amplifier (SOA) in the laser cavity as a phase modulator to suppress the homogeneous line broadening is presented. The analysis reveals that the phase shift introduced by the SOA-based phase modulator is more significant than that formed using a LiNbO/sub 3/ phase modulator, which leads to a better suppression of the homogeneous line broadening. Multiwavelength lasing with small wavelength spacing and improved stability at room temperature is achieved. A fiber-ring laser based on the proposed approach is implemented. Stable multiwavelength operation with up to 26 wavelengths and wavelength spacing as small as 0.19 nm at room temperature is demonstrated.