The Strathclyde University spin-out confirmed Seonaidh MacDonald, formerly of Babcock International Group, HEROtsc, IBM and Hebridean Power, will now lead the company.
Founder Dr Jim Bonar moves from the chief executive post to take up the newly created role of chief technical officer.
MLED chairman Nick Kuenssberg said: "Jim has been terrific but he is a technology guy and we were increasingly asking him to do everything from developing the technology to sort out deals and meet customers.
"We have been very fortunate to get Seonaidh who is a pretty phenomenal hire for a company of our size."
The latest funding round was done with existing shareholders with the mLED board putting in £250,000 and the University of Strathclyde investing £100,000.
Braveheart Investment Group and the Scottish Co-Investment Fund led a £378,000 funding in June last year.
MLED raised £150,000 in seed funding when it spun out from Strathclyde's Institute of Photonics in 2010.
Mr Kuenssberg said the latest money will be used in areas including product development and research while also allowing the business to hire additional staff when its first commercial contracts are finalised.
The financing also provides the company, which makes extremely bright and small lighting sources, with enough cash to take it through to a larger funding round pencilled in for 2014. It is currently working with customers in areas including scopes and range finders, lithography and near to eye displays.
Mr Kuenssberg said: "We are working on one project which if the deal comes off might need us to add a few people straight away.
"It depends when our customers start to order but the people we are looking to bring in will be serious scientists and engineers. They won't be here just to man a desk.
"Scotland is a great place to be as there are lots of people with the requisite knowledge."
While Mr Kuenssberg could not reveal the names of the organisations mLED is working with he suggested they were large corporate entities which were among the biggest in their respective markets.
He said: "We have been delighted to get in the door of these major players as a small start-up.
"I think [this business] is really going to go places."
Mr MacDonald, who invested his own money in the fundraising, formally took up his new role this week and said: "It is a really exciting time and I am going to be working hard to make sure we get some contracts over the line and into volume manufacturing.
"We have a really exciting technology which has applications across a range of sectors.
"I have a feeling I won't be out of pocket on this [investment]."