thank you for your question in our vibrant community.
As for your question here is what I fiund out:
1. The Refugee Travel Document is a substitute for the passport of the state from which you have fled, in other words, where you previously had your legal residence. In Article 28 of the Geneva Convention on Refugees, all Contracting States are obliged to issue a travel document for recognised refugees. That is why this travel document is called the Convention Passport. In Germany, many call it a Blue Passport („Blauer Pass”) because of its colour, but it is not blue in all the countries which joined the convention.
2. Normally, with your blue passport and a visa, you can travel freely in all countries, except for the state that has persecuted you („Verfolgerstaat“) or your country of origin. The member states of the Schengen zone and the members of the European Council which have signed the European Convention on Abolition of the Compulsary Visas for Refugees on 20 April 1959, do not require a visafrom recognised refugees and asylum seekers with a blue passport.
3. The invitation letter of your girlfriend will help you with the applicatrion and also the fact that you are working in Germany.
4. For the Visa procedure please visit: https://de.usembassy.gov/visas/nonimmigrant-visas/
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