Film-Tech Forum ARCHIVE: Dolby 3D with laser light sources?

This is topic Dolby 3D with laser light sources? in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=001349

Posted by Mattias Mattsson (Member # 4308) on 01-20-2013, 09:59 AM:

I have seen it mentioned but never had it confirmed:

Will 3D systems based on Wavelength Multiplex Visualization such as Dolby 3D, Panavision or Infitec be usable when Xenon light sources are replaced with Laser?

Posted by Carsten Kurz (Member # 5396) on 01-20-2013, 10:32 AM:

We don't know yet. Technically, narrow band sources like Lasers would be a very effective way to implement spectral separation. The problem is - you do not only need a suitable set of RGB lasers for 2D, but then a set of 6 matched frequency lasers, all with the neccessary provisions for despecle, etc. While there are tunable lasers, I doubt that they are available with enough tuning bandwith AND power for projection applications.

Same for LED light sources. They are available with a selection of different frequencies, but not enough to make a good choice for two full RGB sets with the neccessary other features for projection applications.

It's much easier to implement polarization 3D with LIPs. Plus, these will be used in very large auditoriums, so also economically, cheap passive polarization glasses will be the natural choice there.

- Carsten

Posted by Jussi Siponen (Member # 5572) on 01-23-2013, 08:55 AM:

Laser sources present (at least in theory) an opportunity to improve the efficiency of the wavelength based systems.

The whole filter wheel assembly in the projector can be eliminated if the light source
a) can switch between the high set and the low set of primary colors
b) switching is fast enough

I have no idea how fast a tunable laser can jump between two wavelengths. Switching two sets of lasers (both sets having three fixed wavelengths) on and off can certainly be done *much* faster than required for image multiplexing. Also, in this arrangement the dark time can be zero.

And for 2D presentations both sets of lasers can be turned on (possibly with reduced output levels).