In {HEAD ~ any event}, {TAIL ~ the temperature tuning coefficient} should be zero or approximately equal to zero to minimize any variation in the center wavelength due to temperature  
In { HEAD ~ any event } , { TAIL ~ the temperature tuning coefficient } should be zero or approximately equal to zero to minimize any variation in the center wavelength due to temperature
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH