public sealed class LasDataset : ArcGIS.Core.Data.Dataset, System.IDisposable  

public async Task OpenLasDataset()
{
  try
  {
    await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
    {
      string path = @"d:\Data\LASDataset";
      var fileConnection = new FileSystemConnectionPath(new Uri(path), FileSystemDatastoreType.LasDataset);

      using (FileSystemDatastore dataStore = new FileSystemDatastore(fileConnection))
      {
        string name = "utrecht_tile.lasd";      // can specify with or without the .lasd extension

        using (var dataset = dataStore.OpenDataset<ArcGIS.Core.Data.Analyst3D.LasDataset>(name))
        {

        }
      }
    });
  }
  catch (GeodatabaseNotFoundOrOpenedException exception)
  {
    // Handle Exception.
  }
}

//Must be on the QueuedTask.Run()

Envelope extent;
SpatialReference sr;
using (var tin = tinLayer.GetTinDataset())
{
  using (var tinDef = tin.GetDefinition())
  {
    extent = tinDef.GetExtent();
    sr = tinDef.GetSpatialReference();
  }
}

using (var terrain = terrainLayer.GetTerrain())
{
  using (var terrainDef = terrain.GetDefinition())
  {
    extent = terrainDef.GetExtent();
    sr = terrainDef.GetSpatialReference();
  }
}

using (var lasDataset = lasDatasetLayer.GetLasDataset())
{
  using (var lasDatasetDef = lasDataset.GetDefinition())
  {
    extent = lasDatasetDef.GetExtent();
    sr = lasDatasetDef.GetSpatialReference();
  }
}

//Must be on the QueuedTask.Run()

var lasCP_ds = new LasDatasetLayerCreationParams(lasDataset);
lasCP_ds.Name = "My LAS Layer";
lasCP_ds.IsVisible = false;

//Create the layer to the LAS dataset
var lasDatasetLayer_ds = LayerFactory.Instance.CreateLayer<LasDatasetLayer>(lasCP_ds, map);

//Must be on the QueuedTask.Run()

var lasCP_renderers = new LasDatasetLayerCreationParams(lasDataset);
lasCP_renderers.Name = "My LAS Layer";
lasCP_renderers.IsVisible = false;

// create a point elevation renderer
var ptR = new LasStretchRendererDefinition();
// accept all defaults

// create a simple edge renderer
var edgeR = new TinEdgeRendererDefintion();
// accept all defaults

// add renderers to dictionary
var l_dict = new Dictionary<SurfaceRendererTarget, TinRendererDefinition>();
l_dict.Add(SurfaceRendererTarget.Points, ptR);
l_dict.Add(SurfaceRendererTarget.Edges, edgeR);

// assign dictionary to creation params
lasCP_renderers.RendererDefinitions = l_dict;

//Create the layer to the LAS dataset
var lasDatasetLayer_rd = LayerFactory.Instance.CreateLayer<LasDatasetLayer>(lasCP_renderers, map);