diff --git a/mods/lzr_globals/init.lua b/mods/lzr_globals/init.lua
new file mode 100644
index 0000000..b219c5b
--- /dev/null
+++ b/mods/lzr_globals/init.lua
@@ -0,0 +1,5 @@
+lzr_globals = {}
+
+lzr_globals.PLAYFIELD_START = { x = -50, y = 0, z = -50 }
+lzr_globals.PLAYFIELD_SIZE = { x = 100, y = 100, z = 100 }
+lzr_globals.PLAYFIELD_END = vector.add(lzr_globals.PLAYFIELD_START, lzr_globals.PLAYFIELD_SIZE)
diff --git a/mods/lzr_laser/init.lua b/mods/lzr_laser/init.lua
index 077b7ba..f441667 100644
--- a/mods/lzr_laser/init.lua
+++ b/mods/lzr_laser/init.lua
@@ -4,3 +4,4 @@ dofile(minetest.get_modpath("lzr_laser").."/util.lua")
 dofile(minetest.get_modpath("lzr_laser").."/laser.lua")
 dofile(minetest.get_modpath("lzr_laser").."/blocks.lua")
 dofile(minetest.get_modpath("lzr_laser").."/physics.lua")
+dofile(minetest.get_modpath("lzr_laser").."/tools.lua")
diff --git a/mods/lzr_laser/mod.conf b/mods/lzr_laser/mod.conf
index 32a794a..05f6638 100644
--- a/mods/lzr_laser/mod.conf
+++ b/mods/lzr_laser/mod.conf
@@ -1 +1,2 @@
 name = lzr_laser
+depends = lzr_globals
diff --git a/mods/lzr_laser/physics.lua b/mods/lzr_laser/physics.lua
index 77ce563..930faf9 100644
--- a/mods/lzr_laser/physics.lua
+++ b/mods/lzr_laser/physics.lua
@@ -75,7 +75,7 @@ function lzr_laser.travel_laser(pos, dir)
 end
 
 -- Remove all lasers in area and disable all laser blocks
-function lzr_laser.clear_lasers_in_area(pos1, pos2)
+function lzr_laser.clear_lasers_in_area(pos1, pos2, ignore_emitters)
 	-- Remove lasers
 	local lasers = minetest.find_nodes_in_area(pos1, pos2, {"group:laser"})
 	minetest.bulk_set_node(lasers, {name="air"})
@@ -86,7 +86,11 @@ function lzr_laser.clear_lasers_in_area(pos1, pos2)
 		local block_pos = laser_blocks[b]
 		local block = minetest.get_node(block_pos)
 		local def = minetest.registered_nodes[block.name]
-		if def then
+		local is_ignored_emitter = false
+		if ignore_emitters ~= true then
+			is_ignored_emitter = minetest.get_item_group(block.name, "emitter") > 0
+		end
+		if def and not is_ignored_emitter then
 			local inactive = def._lzr_inactive
 			if inactive then
 				minetest.set_node(block_pos, {name=inactive, param2=block.param2})
@@ -94,3 +98,16 @@ function lzr_laser.clear_lasers_in_area(pos1, pos2)
 		end
 	end
 end
+
+-- Emit lasers from all active emitters
+function lzr_laser.emit_lasers_in_area(pos1, pos2)
+	local emitters = minetest.find_nodes_in_area(pos1, pos2, {"group:emitter"})
+	for e=1, #emitters do
+		local epos = emitters[e]
+		local emitter = minetest.get_node(epos)
+		local is_active = minetest.get_item_group(emitter.name, "emitter") == 2
+		if is_active then
+			lzr_laser.emit_laser(emitters[e])
+		end
+	end
+end
diff --git a/mods/lzr_laser/tools.lua b/mods/lzr_laser/tools.lua
index 7d32e0d..1ffb591 100644
--- a/mods/lzr_laser/tools.lua
+++ b/mods/lzr_laser/tools.lua
@@ -15,11 +15,16 @@ minetest.register_tool("lzr_laser:emit_toggler", {
 			return itemstack
 		end
 		local def = minetest.registered_nodes[node.name]
+		-- Deactivate emitter
 		if def._lzr_inactive then
 			minetest.swap_node(pos, {name=def._lzr_inactive, param2=node.param2})
+			lzr_laser.clear_lasers_in_area(lzr_globals.PLAYFIELD_START, lzr_globals.PLAYFIELD_END)
+			lzr_laser.emit_lasers_in_area(lzr_globals.PLAYFIELD_START, lzr_globals.PLAYFIELD_END)
+		-- Activate emitter
 		elseif def._lzr_active then
 			minetest.swap_node(pos, {name=def._lzr_active, param2=node.param2})
-			lzr_laser.emit_laser(pos)
+			lzr_laser.clear_lasers_in_area(lzr_globals.PLAYFIELD_START, lzr_globals.PLAYFIELD_END)
+			lzr_laser.emit_lasers_in_area(lzr_globals.PLAYFIELD_START, lzr_globals.PLAYFIELD_END)
 		end
 		return itemstack
 	end,