[j-nsp] DWDM 10Gig transmit power

[Good One]

I am trying to find out what is causing my link to go down either the transmit power or a receive power. Below are the parameters of link having a connectivity issue of DWDM transmission. The problem is sometimes it works and sometime it does not and transmission guys keep insisting that your transmit power is low. Now the question is if the transmit power is low, can you increase it for a particular link. Physical interface: xe-4/2/0    Laser bias current                        :  33.111 mA    Laser output power                        :  0.4410 mW / -3.56 dBm    Module temperature                        :  30 degrees C / 86 degrees F    Laser rx power                            :  0.2516 mW / -5.99 dBm
I have another link over same DWDM transmission which is working quite fine for days. The following are the parameters for that link.
Physical interface: xe-4/3/0    Laser bias current                        :  32.748 mA    Laser output power                        :  0.5060 mW / -2.96 dBm    Module temperature                        :  31 degrees C / 88 degrees F    Laser rx power                            :  0.2538 mW / -5.96 dBm
I would appreciate it if someone can describe it in detail that what could be the reason causing this link to fluctuate randomly. 
Thanks
Andrew