Letters of Invitation

The application process for an international visa can take up to six months or more. You will need to apply for your visa as early as possible, but no later than three months before you wish to enter the US.

One factor that increases the processing time is the personal interview, now required for most applicants as a standard part of visa processing. As soon as you know that you will need a visa for travel, you should contact the embassy or consulate to schedule an appointment for screening.

Individuals requiring letters of invitation to obtain travel visas may contact OSA directly by one of the following methods:

1. Email
   invitations@osa.org
2. Fax
   +1 202.416.6100
3. Mail
   Optical Society of America, Meetings Department
   2010 Massachusetts Ave. NW
   Washington, DC 20036

Please include your full name as it appears on your passport, your complete mailing address, and your phone and fax numbers. Be sure to indicate which meeting you will be attending. If you are presenting a paper, include the title and the session in which that paper will be presented, or if you are exhibiting, please indicate that in your request. When requesting letters for more than one individual, please include all information above for each person. Individuals from China should include the passport number, the date of birth and the gender of each person requesting an invitation letter. All letters of invitation will be sent by airmail or by fax unless a Federal Express account number or credit card number with expiration date is provided on the original request. Please allow ample time for processing requests. OSA is not able to contact US or Canadian Embassies in support of an individual attempting to gain entry into the host country to attend an OSA meeting.