ֳʹáֵ΢͹С۸׷ֱֻ0.1 nmԶԶﲻFBGҪpmķֱ

ΪBraggƯIJȣ˻F-Pɵг˲Ͳ׼òֵ-׷ĴԭʼÿԲһЩ㣬׷õBraggƯ÷ЧңܾȷزBraggƯӶʵָ߾ȵز¶ȡӦ

1 FBGԭ

BraggԭԴĹFBGȥFBGBraggΪĵխ׷ΧڵĹⷴBraggBFBGդAЧneff

ˣFBGԱխ˲˲IJBraggFBGܵӦ䡢¶ȵʹFBGդԻЧneff仯ʱFBGBraggBӦ仯ʽ(1)΢֪BraggƫΪ

Ӷʵ˴ԷźŹIJơˣͨʵʱⷴ䲨ƫٸݡnff֮Թϵɻôı仯

2 ֵ-׷ԭ

׷ںܶFBGϵͳУFBGֻй⹦ʵԼ׵Ưƣ׵״DZֲ䣬ڸ˹ֲԤʾһֿԣBraggƯƿͨȽԭʼƵƯƺƵ׵áԿûغʾȸƵط۷

źŴۣ2׾תֱΪX(i)Y(i)(i=123Nʾ)߻㶨Ϊ

ʽjΪxϵIJƯơ±곬Χ[1N]ƵΪ㡣ݻصʣR(j)x(i-j)Y(i)ص࣬ƵʱõֵΪÿFBGĹ׶ڸ˹ֲԣֻҪȲɼһ׼ףȻʵ׽л㣬ûֵʱӦjֵͿԵõʵ׵ƯƣҲ͵õBraggƯơ

ɼ׷ǿеģҪǴ˷봫ͳķֵⷨȣи߾ȵص㡣ֵⷨǼԭʼеֵƵطͨؼ㣬ΪһϵжӦͬƯֵֵеֵÿֵʱֵ㣬ᰴNƽĹЧʵԭʼеӶ߲ȡƵԿ

ڷǰn1n2໥ǶӸ˹ֲSNRΪźŵľľԭźXn(i)Yn(j)ȾΪSNR0ݸ˹ֲĶԣʽ(6)Ϊ

ʽɼNIJӣԭź˵׷ڲ(ʵкʵ˵)ԣԭʼеIJͿԱơ

Ϊ˽ϵͳӲʵѶȣ֤ٶȣʹȽһߣĻԲֵķĹ̾ԭʼĹÿԲһЩ㣬׷õBraggƯơԲֵĿľΪʹԭʼ׸ƯƺĹףӶ׷иܾȷȷƯ

3 ʵ

ϵͳװͼ1IJΪ1 550 nmķ(LED)׿Ϊ30 nmLEDĹ⾭3 dBFBGFBGصĹٴξ3 dBF-Pɵг˲(FOOL2)پתŴDAתźŴ(DSP)ʵֲֵ-׷(FBG0ǹ̶IJοFBG׼ɵгF-P˲ǻƯƶԲȵӰ)

3.1 ֵ-׷ֵȽʵ

FBG1FBG2ķ10ΣFBG1FBG2ɷã¶ȱֲ䣬ԣϸεĽӦͬʵд΢СIJ졣ͼ21 5521 557nmΧڣ800㣬FBG23ֲͬµIJֵ(FBG1FBG2)

ͼ2Уaôͳֱֵķ׼Ϊ0.042 41 nm bûֵ׷׼Ϊ0 nmcDzòֵ-ط(ÿڵԲֵ8)׼Ϊ0.002 14 nm濴ȥbãʵÿڵ֮ļ̫ڵBraggСʱͲķֿǣգǿͬһֵȲһݣ߷ֱʹԭʼ׸ƯƺĹף׷ͿԻѵЧ

Ϊоֵ-׷Уһ£òٵ㲨ֱߵ⣬ʵϵͳУÿڵ֮IJֵ2ӵ17õ1

ӱ1Կʵвòֵ-׷BraggƯƣ䲨ֱŲֵӶϴӡϵͳֵӵ12ʱֱɴﵽ1 pmӣ޷һơ

3.2 ¶ȴʵ

ÿ10IJ𲽶FBGм£ֵ-׷Bragg仯¶֮Ĺϵͼ3

ͼ3пɵõ֮()Ϊ1.18pm

4

ͨ۷ʵ׷BraggƯǿеģͬʱȣ߽ȡڴ˻ϣԲֵķԭʼÿһĵ㣬Խһ߽ȡòֵһ׷ʹBraggդֱﵽ1 pm¶Ȳȴﵽ0.2档



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