increase power
depends upon data rate
bw of multiplex
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwjtyYrn6M7MAhXHJI4KHatwCPoQFggoMAE&url=http%3A%2F%2Fwww.issr-journals.org%2Flinks%2Fpapers.php%3Fjournal%3Dijisr%26application%3Dpdf%26article%3DIJISR-14-301-03&usg=AFQjCNFq5reRBxXmcjAWxXxd0eJ4Zia2QA&sig2=XBDUgpEACyKBkTx_dUN3jA
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwjtyYrn6M7MAhXHJI4KHatwCPoQFggxMAI&url=http%3A%2F%2Foptiwave.com%2Fresources%2Fapplications-resources%2Foptical-system-16-channel-wdm-system-design%2F&usg=AFQjCNEyZq2mPZDpY7lIe2xAxC56d9pFww&sig2=cIvoY4n_YVpblBH8FHl5qA
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjtyYrn6M7MAhXHJI4KHatwCPoQFgg4MAM&url=http%3A%2F%2Fwww.ciscopress.com%2Farticles%2Farticle.asp%3Fp%3D30886%26seqNum%3D5&usg=AFQjCNEfhAYMaiGnO2FQVPbDgWy3dStH8g&sig2=gxA3_fm2tO1EO96JOuHkhQ
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwjtyYrn6M7MAhXHJI4KHatwCPoQFghKMAY&url=http%3A%2F%2Fwww.ijltet.org%2Fwp-content%2Fuploads%2F2013%2F08%2F4.pdf&usg=AFQjCNHeaC6bKig_RPBJtTxkDJmbw-JAWQ&sig2=DyO-nPL10e4-HC9hnfvZBw
https://books.google.co.in/books?id=8IcNZu1smOwC&pg=PA54&lpg=PA54&dq=wdm++with+high+quality+factor&source=bl&ots=5ugGXyKW60&sig=dreBv4HC8UoPeOheDIoDooKDPCE&hl=en&sa=X&ved=0ahUKEwjtyYrn6M7MAhXHJI4KHatwCPoQ6AEIVjAI