Reflection holography (Lippman-Denisyuk) is well-developed direction that really  needs the CW extra stabilized diode lasers. Up to now only He-Ne CW laser and some nanosecond pulsed lasers have satisfied demands of the reflection holography  

The requirement is for the coherence length of the light source to be significantly greater than the differential path lengths in the object being imaged, when the coherence length is measured over the hologram exposure duration. In other words on might use a source that fluctuates in frequency, provided it does not fluctuate during the exposure duration.

To make a hologram, light coming from a test object and a reference wave are coherently superimposed to convert the phase information into detectable intensity modulations. From the resulting intensity pattern information on the phase can be extracted using phase shifting techniques. Thereafter, the optical path difference is identified and thus the shape of the test object as an example could be obtained. However, Holography have high demands regarding both temporal and spatial coherence of the illumination. Accordingly, spatially filtered monochromatic laser light is used for illumination; since it has good temporal coherence i.e. a well-stabilized laser has a temporal coherence length of several km.

If the coherence length is too long, you will pick up a lot of noise from objects far from your sample.