The problem is that "focused" does not really mean "concentrated"
Everyone that has ever played with a magnifying glass "know" that you can take the light from the Sun and turn it into an infinitely concentrated dot. This is in essence a variant what you are trying to do.
The problem here is two things:
The only reason you can get a dot that small is because the magnifying glass is very close to the "target", compared to the distance to the light source.
That is not actually an infinitely concentrated dot; it is a focused image of the Sun.
That is not a very small dot of light, that is an image of the Sun. (Image source)
It turns out that you cannot gather up light and make it go in a beam that is more narrow leaving your light gathering device than it was when it came in. The light beam will always be at least as wide, or wider. To explain this in full detail requires a university course in optics, but in short the principle is called The Conservation of Étendue, and if you want some really hard science I encourage you to read on that link. But it is way too advanced — and it will not serve anyone's purpose — to quote that in full here.
So you will forgive me if I focus the answer a bit. Or rather: concentrate it. ;) And if the answer below seems boring or hard to grasp, I recommend xkcd: what if #145.
When you use optics to move light from a light source, and project it somewhere else, the smallest you can make the projected light is when you attain an image of the light source that is in perfect focus. "In focus" in this case does not mean "concentrated to a very small spot", but instead means that you can see every detail of the light source clearly, because it is not blurred. Simple rules of optics dictate that you can not make the projected light any smaller than this.
The next rule of optics say that the perfect way to project a light source some place else is the pinhole "lens". With a pinhole you will always attain a perfectly focused projection, so with a pinhole, you will always attain the smallest projection.
The next rule of optics say that an infinitely small and perfectly flat mirror is like a pinhole, only that it has the added benefit of being able to bounce the projected image in some other direction.
Yet another rule of optics says that every lens — like the magnifying glass above or in the case of the question: your sun beam device — can be approximated by assuming it consists of an infinite number of infinitely small mirrors. The projection from the lens is just all of these images from the mirrors overlaid on each other.
Now comes the kicker:
The size of a perfectly focused image, using a pinhole, is proportional to the original in the same way that the distance between the lens and the image, and the lens and the light source is proportional to each other.
If you divide the size of the image with the size of the original, you get a ratio... say 1 to 10, the image is 10 times smaller.
That ratio is the same as between the distance from the hole to the image, and the distance from the hole to the original. So if the camera is 1 meter deep, then the distance to the tree is 10 meters.
For your project this means that this "lens" of yours — and I say again: all lenses, optics and other such devices can be approximated by an infinite numbers of mirrors, that in turn are like pinholes — must be closer to Titan than to the Sun. Otherwise the projected image of the Sun on Titan will be larger than the Sun itself and therefore weaker in intensity; you gain as near to nothing it makes no odds.
Assuming you want this focusing device of yours to not waste any sunlight by making it fall outside of Titan, the image of the Sun must be smaller than Titan itself. And since the ratio between the size of the Sun and the size of Titan is about 279 : 1, it will not really make any sense to use this scheme of yours until you have gotten your concentrating device so close to Titan that the distance from this device to Titan, divided by the distance from the device to the Sun, is 1 over 279...
... i.e. you are nearly there anyway.
You might as well then put your reflectors in orbit around Titan and harvest the sunlight there. This also means that you do not need to spread it all over Titan but can put it in spots of greater importance.