Digital Isolator vs Optocoupler?

[ftransform]

So I ordered a digital isolator, not really considering how it works, and when I read the datasheet to my alarm I found out that it uses radio signals to transmit information.
Since I want to use it to communicate serial from a ADC I got paranoid about it being a noise source.

I found one mention of this potential problem on dangerousprototypes.com but I cannot find information on google.
To me it seems that putting a radio frequency transmitter right next to my ADC is a big no no, or are these devices nice and quiet? Since it was not mentioned in the datasheet (for instance analog devices icoupler system) to be low noise I expect it to be a problem.

Has anyone here used these devices next to a sensitive ADC and determined if they are detrimental?

Lesson learned to very carefully read the datasheet before purchasing 

I am about to jury rig some bullshit out of shrink tubing, photodiodes and LED's because I am broke 
I got this thing http://www.digikey.com.au/product-detail/en/SI8431AB-D-IS/336-1758-5-ND/2170665

Is it worth pursuing a optical method?

[digsys]

The Silabs isolators are one of the best around. I use many 100s, in many designs. There is NO, or negligible spurious
radiation emission, and I've never heard of an issue near adc's. IF you want to be extra-certain, put 10/100pF ceramic
caps right at the inputs. No need to panic :-)
Edit: The advantages are WELL worth it as well.

[ftransform]

The Silabs isolators are one of the best around. I use many 100s, in many designs. There is NO, or negligible spurious
radiation emission, and I've never heard of an issue near adc's. IF you want to be extra-certain, put 10/100pF ceramic
caps right at the inputs. No need to panic :-)
Edit: The advantages are WELL worth it as well.

Good to know I was ripping my hair out looking for a cheap optical solution. 
I wish they would advertize that fact better. It looks like a discrete optical solution for 6 lines would cost me 30$+, so I am very happy to get away with 5$.
I will also put some ferrite on the power rail for it. 

[andete]

Very interesting, as a newbie, I didn't even knew these digital isolators exist.

The link mentioned in the original post: http://www.digikey.com.au/product-detail/en/SI8431AB-D-IS/336-1758-5-ND/2170665

actually contains a hyperlink named Digital Isolators vs. Optocouplers that has a video showing the basics of the device.

[digsys]

For the price, they're pretty awesome. 1 / 10MHz transfer, ultra-low jitter/skew, pretty much fixed 1.6mA over the range.
Perfect for SPI, SCI, CAN, USB etc

[knarf.be]

A good advice: always sleep a night over every decision, mostly you won't  regret it!
Yesterday I wanted to buy a DMM from a local store, but it costed € 100, so I slept a night over it, and today I found a DMM well better than the € 100 (true RMS) for € 50 here on the forum.
Always sleep a night over something when you have the time

[ftransform]

A good advice: always sleep a night over every decision, mostly you won't  regret it!
Yesterday I wanted to buy a DMM from a local store, but it costed € 100, so I slept a night over it, and today I found a DMM well better than the € 100 (true RMS) for € 50 here on the forum.
Always sleep a night over something when you have the time

Then this project would take 3 billion years 

[mikeselectricstuff]

NVE Also do a big range of digital isolators, including these neat ones with passive inputs

[c4757p]

these neat ones with passive inputs

Those are pretty cool.