Optical add/drop filters are key components of wavelength-division multiplexing (WDM) systems, and are going to break through the main obstacle to extend fiber-to-the-home (FTTH) by reducing the cost.
具有波长选择能力的光上下话路滤波器是波分复用系统中的一种关键器件,也是降低成本、推广光纤到户光网络的突破口。
The Transmission Spectra of Phase-Shifted Fiber Grating and Its Applicationin Optical Add-Drop Multiplexer
相移光栅的特性及其在上下话路复用器中的应用
Study on Photosensitive Erbium Doped Optical Fibers and Bragg Grating-Assisted Coupler for Add/Drop Filters
光敏掺铒光纤和光纤布拉格光栅辅助耦合器型上下话路滤波器的研制
When my words were acted upon at lower levels, order was immediately restored on the railways.
这个话传下去以后，铁路上的秩序马上就好了。
fit a listening device to(a telephone line)
在（电话线路）上装窃听器
Give me a buzz before you set off.
上路之前给我来个电话。
Sam had stopped en route to telephone and arrange luncheon at the Garden House Hotel.
萨姆半路上停下车去打电话，安排在“花园饭店”吃午饭。
How did you spend your time on the road?
【每日互动话题】上班路上如何打发时间？
A second generation of ADSL will increase the downstream speed to 6Mbps and allow simultaneous video and voice transmission over the same line.
第二代ADSL将把下游速度提高到6Mbps，并同时允许在同一线路上游送视频图像和话音。
Actually, if you could grab that other suitcase there, it would save a trip back to the car.
事实上，如果你可以拿那边的另一个行李箱的话，我就可以省下一趟走到车子的路。
touched 19 on the phone to get room service.
轻按电话机上的号码19 以接通房间的电话线路
call for assistance machine [Mass Transit Railway]
乘客求助紧急通话机〔地下铁路〕
Somebody down in the street is looking up at you!"
下边马路上有人看你
top bottom pincushion correction circuit
上下枕形畸变校正电路
The road caved in above the old mine.
旧矿上面的路面下沉了。
add/drop multiplexer
上行/下行多路复用器
a high level [a surface, an underground, a submarine] railway
高架[地上, 地下, 海底]铁路
Base course [highways]: The part of a road structure Below the wearing course and above the road Base.
基层[公路]: 路面层之下路基之上的道路结构部分。
Don't hang up, please. I'll have the call transferred to another line.
请别挂。我把电话转到另一条线路上去。
