Building 10, Masur Auditorium, National Institutes of Health
Bethesda, MD, United States
24 - 25 September 2015
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Visa Information and Invitation Requests

Apply now for your Visa

Because of the number of visa applications and the need for thorough security reviews, the visa application process can take several months. It is strongly encouraged travelers to apply for their visas as early as possible (at least 3 to 4 months before the visa is needed).  

Passport Requirements to Enter the United States

  • As of 31 December 2006, anyone traveling to or from the US via air or sea from Canada, Mexico, Central and South America, the Caribbean, and Bermuda must have a passport or other secure, accepted document to enter or re-enter the US.
  • As of 1 June 2009, the above requirement extends to all land border crossings, as well as air and sea travel.
  • Beginning 12 January 2009, visitors to the U.S. from visa-waiver countries, most of which are in Europe, will be required to register online and to be screened and authorized for entry. The European Commission is considering a similar system later for visitors from the U.S. and other countries. The new Electronic System for Travel Authorization (ESTA) was ordered by the Department of Homeland Security to identify visitors who might be a threat. Authorization is good for two years or until one's current passport expires. The initial registration can take place any time before the first trip to the U.S. after the system goes into effect.

Online Resources

Register Online for entry to the United States

U.S. Department of State Visa information home page:

Estimated wait times for interview appointment and visa processing:

Do you need a visa? See information for temporary visitors to the United States:

U.S. State Dept. Temporary Visas:

Department of Homeland Security:

National Academy of Sciences:

Letter of Invitation

FOR CONFERENCE CHAIRS, TECHNICAL COMMITTEE MEMBERS, AND AUTHORS: Individuals requiring letters of invitation to obtain travel visas must be listed on a paper or in the program to receive an invitation letter. If you are in need of an Official Invitation Letter from SPIE for visa application purposes, please fill out and send the Invitation Letter Request Form.

We recommend that you secure your travel visa before registering for the conference as cancellations after the preregistration cutoff may result in a cancellation fee.

Visa Guidelines

Visa Background Information

Because of the number of visa applications and the need for thorough security reviews, the visa application process can take several months. It is strongly encouraged travelers to apply for their visas as early as possible (at least 3 to 4 months before the visa is needed).

Contact the nearest U.S. consulate or embassy for details on visa application procedures.

Guidelines for Successful Visa Applications:

  • Visa applicants are expected to provide evidence that they are intending to return to their country of residence. This may include documentation of the following:
    • family ties in home country or country of legal permanent residence
    • property ownership
    • bank accounts
    • employment contract or statement from employer stating that the position will continue when the employee returns
  • Visa applications are more likely to be successful if completed in a visitor's home country than in another country
  • Applicants should present their entire trip itinerary, including travel to any countries other than the United States, at the time of their visa application
  • Include a letter of invitation from the meeting organizer or the U.S. host, specifying the subject, location and dates of the activity, and how travel and local expenses will be covered
  • If travel plans will depend on early approval of the visa application, specify this at the time of the application
  • Provide proof of professional scientific and/or educational status (students should provide a university transcript)
  • Any evidence that establishes a prior record of business travel to exhibitions and other events is helpful. A photograph of an applicant staffing an exhibit booth, receipts for admission, purchases of goods and services to support an exhibit booth at an event, are all potentially valuable evidence that may tip the balance in favor of visa approval.

A successful candidate will come to an interview with:

  • Evidence of prior related business travel, even travel to countries other than the United States (US).
  • A business resume written in English.
  • A letter of invitation containing anti-counterfeit measures from the sponsoring organization, such as SPIE, as well as personal information about the applicant such as a passport number, Paper Number, etc.

Even those who have traveled frequently to the US for business purposes might encounter difficulties from time to time that might have little to do with their standing as individuals. The nature of the products and/or industry in which they have become involved such as certain types of US controlled goods (wireless technology, electronics, and such) may give rise to difficulties and/or delays. The political climate and current state of relations between the nations may become a factor. In other words, a prior history of travel to the US is never a guarantee of future admission.

Visa Difficulties

SPIE does not have any influence with the State Department or the Office of Homeland Security. If your visa is delayed (60 days or longer) or denied, please contact the consulate where your application is being processed. Also, please contact the National Academy of Sciences International Visitors Office and fill out the questionnaire:

The International Visitors office regularly reports to the State Department (submitted through the Visa Questionnaire) about applications which have been pending for longer than 60 days.