[转帖]An 8-skip-0 WDM filter

xx_912

An 8-skip-0 WDM filter is capable of adding or dropping 8 channels of a 100-GHz spacing fiberoptic telecommunication system. The design we present has the following specifications:
<UL>
4 v' A( @! y" w4 _+ ^, x8 R<LI>centered at 1550 nm,
<LI>passband width of 6.0 nm at the -0.5 dB (about 89%) transmission level,
% z; u* ]7 w( u. \% y6 Y# N<LI>bandwidth of 6.8 nm at the -25 dB (about 0.3%) transmission level,
& ]9 z" H" p6 L4 b2 F<LI>0.1% ripple in the passband
<LI>materials H (index 2.065) and L (index 1.47) </LI></UL>
<P>TFCalc 3.5 has the capability of designing narrow bandpass (NPB) filters using the prototype method. To obtain the steep edges required in this design, we used 13 cavities. After a few minutes, TFCalc produced a design whose performance is shown below.
<P>
& D" V4 y( B1 |7 b<P align=center><IMG src="http://www.sspectra.com/designs/8-skip-0.gif"> </P>The design's width at the -25 dB level is 6.7 nm, which is better than required. The stack formula for this 303-layer design is <PRE>HLHLHLHL 3H
3 V& o$ {0 s7 p5 x! d" h2L
HLH 3L HLHLHL 3H LHLHLHL 3H LH
% S2 \; }+ j: o2L
' h- p9 g2 H. N+ o! nHLHLHLH 3L HLH 3L HLHLHLH 3L HL 3H
2L
+ {9 k% c% L$ k  z4 G+ i5 {3H LHLHLH 3L HLH 3L HLHLH 3L HLHL 3H
  n% M. p4 T7 T- o3 O! F& i  m2L
H 3L HLHLHLH 3L H 3L HLHLHLHLH 3L 3H
2L
3H LH 3L HLHLHLH 3L HLHLH 3L HLHL 3H
3 f& S& E2 l8 U& l) W& u/ O2L
6 k; }1 U6 a" J# c' d3H LHLHLHLHLH 3L HLH 3L HLHL 3H L 3H
, _) c- B2 L: y8 p# _2L
3H L 3H LHLH 3L HLH 3L HLHLHLHLHL 3H
% u2 m3 A4 c1 ]2L
3H LHLH 3L HLHLH 3L HLHLHLH 3L HL 3H
" A2 J) _/ i* ^5 L: M6 y9 v& H2L
, l9 {  Z0 B( ]( `1 D! o# r3H 3L HLHLHLHLH 3L H 3L HLHLHLH 3L H
+ a4 p' [/ M1 _! v! M2L
4 x3 X* `& S  y3H LHLH 3L HLHLH 3L HLH 3L HLHLHL 3H
2L
3H LH 3L HLHLHLH 3L HLH 3L HLHLHLH
2L
" S0 \- s3 ?, R  p( }HL 3H LHLHLHL 3H LHLHLH 3L HLH
) }# Z6 d6 |( b6 Y2L
3H LHLHLHLH
# S3 e  Q- R% o7 b# g8 _- I* R( d</PRE>

kaixinkele

高手，我怎么看不懂，请搞通俗一点吗。

opto-tech

http://www.opto-tech.com/read.php?tid=77

rotarynife

高手，我怎么看不懂，请搞通俗一点吗。

lzh1234