To Jovi-Yvon, about the damaged grating

Original:

    Yes, we did understand that the grating exhibits a burn mark probably due to the oil coating or laser damaged.But the reason why we send back to you is to make sure which one indeed makes the grating exhibits a burn mark. If it was a laser-damaged problem, it was no doubt that we used the grating under your specification on the quotation (0.1 to 0.2J/cm2 for fs pulse). If so, that is your grating didn't reach your specification. And next time we will buy grating from other manufacturer, which can provide the specification we need. If it was an oil coating problem, now we had set up a cold-trap closed to the compressor to avoid the oil coating problem happened again. And we hoped that you shall clean it and then we would buy another from you.

Modified:

Dear Sir:

     We do understand that  the burn mark on the grating was probably caused by the oil coating or laser damage. However, the reason why we sent it back to you was to make sure which one of these made the burn mark.

     If it was a laser damage problem, then it is obvious that the grating doesn't conform with the specifications shown on the quotation (it is no doubt that the laser energy flux we used was below your specification on the quotation, i.e., 0.1 to 0.2J/cm2 for fs pulse). In this case, we will need to find other manufacturers that can provide the gratings with the specifications we need.

    On the other hand, if it was an oil coating problem, then we can avoid this by setting up a cold trap close to the compressor to trap the oil. In this case, we can buy new gratings from you to replace the damaged one. Better yet, we were hoping that you may have a way to clean it. If you can clean it, then we can identify it to be an oil coating problem and we can send it back for cleaning whenever this happens again.

    Is there any way you can find out the answer or try to clean it? This is very important to us. Thank you for your patience.