birthday card

教授

生日快乐! 很高兴认识你去年。 This is not considered respectful since a teacher is of highest esteem.  I suggest,

尊師生日快乐, 感恩不尽能得去年你的教 /義/導/

{pinyin for me: jiàoshòu, shēng rì kuài lè! hěn gāoxìng rènshí nǐ qù nián}

birthday card

教授

生日快乐! 很高兴在去年能认识您！

{pinyin for me: jiàoshòu, shēng rì kuài lè! hěn gāoxìng zai qu nian neng ren shi nin

birthday card 生日贺卡

教授您好：

生日快乐! 很高兴认识你去年 【1】。

{pinyin for me: jiàoshòu, shēng rì kuài lè! hěn gāoxìng rènshí nǐ qù nián}

【1】“很高兴认识你去年 ” more natural express: 很高兴去年认识您！or 很高兴认识您一年了！

I think you would like to gift more blessings! I'd like to recommend your some examples, like:

我认为你还想送上更多的祝福！我想向你推荐一些的例句，比如:

I wish you would get more academic achievements and would have students all over the world!

我祝愿您的学术成就更上一层，桃李满天下！

You can also express your meaning both in Chinese and English. We can give your advise and let it more accurate. 

你也可以用中文和英文表达你的意思，我们能给你提建议，让内容更准确。