diff --git a/src/JuliaFEM.jl b/src/JuliaFEM.jl
index 11f1964..ccd78ed 100644
--- a/src/JuliaFEM.jl
+++ b/src/JuliaFEM.jl
@@ -120,9 +120,6 @@ export AbstractSolver, Solver, Nonlinear, NonlinearSolver, Linear, LinearSolver,
 include("solvers_modal.jl")
 export Modal
 
-include("optics.jl")
-export find_intersection, calc_reflection, calc_normal
-
 ### Mortar methods, contact mechanics extension ###
 include("problems_contact.jl")
 include("problems_contact_2d.jl")
diff --git a/src/optics.jl b/src/optics.jl
deleted file mode 100644
index 700e3f1..0000000
--- a/src/optics.jl
+++ /dev/null
@@ -1,128 +0,0 @@
-# This file is a part of JuliaFEM.
-# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
-
-function gen_rtic_grid!{S<:Union{Seg2,Seg3}}(thetas, element::Element{S}; npts=2)
-    xi1 = midpoints(linspace(-1, 1, npts+1))
-    for xi in xi1
-        push!(thetas, [0.0, xi])
-    end
-end
-
-function gen_rtic_grid!(thetas, element::Element{NSeg}; npts=2)
-    knots_u = element.properties.knots
-    u = midpoints(linspace(minimum(knots_u), maximum(knots_u), npts+1))
-    for ui in u
-        push!(thetas, [0.0, ui])
-    end
-end
-
-function gen_rtic_grid!(thetas, element::Element{NSurf}; npts=2)
-    knots_u = element.properties.knots_u
-    knots_v = element.properties.knots_v
-    u = midpoints(linspace(minimum(knots_u), maximum(knots_u), npts+1))
-    v = midpoints(linspace(minimum(knots_v), maximum(knots_v), npts+1))
-    for ui in u
-        for vi in v
-            push!(thetas, [0.0, ui, vi])
-        end
-    end
-end
-
-"""
-Find intersection between element surface X(ξ) and ray x(t) = s + t*n by
-solving equation F(t, ξ) = x(t) - X(ξ) = 0
-
-Returns
--------
-t, ξ
-
-References
-----------
-[1] https://en.wikipedia.org/wiki/Ray_tracing_%28graphics%29
-
-"""
-function find_intersection{S<:Union{Seg2, Seg3, NSeg, NSurf}}(element::Element{S}, s, n, time;
-    max_iterations=10, tolerance=1.0e-12, info_output=false, deformed=true, secondary=false, npts=2)
-
-    x = element["geometry"](time)
-    if deformed && haskey(element, "displacement")
-        x += element["displacement"](time)
-    end
-
-    function calc_intersection!(theta)
-        i = 0
-        dtheta = zeros(theta)
-        for i=1:max_iterations
-            t = theta[1]
-            xi = theta[2:end]
-            N = get_basis(element, xi, time)
-            dN = get_dbasis(element, xi, time)
-            A = [n -dN*x]
-            r = s + t*n - N*x
-            try
-                dtheta = A \ -r
-            catch err
-                info("failed to solve equation.")
-                dump(theta)
-                dump(A)
-                dump(r)
-                throw(err)
-            end
-            theta[:] += dtheta
-            info_output && info("iter $i, theta = $theta, norm(dtheta) = $(norm(dtheta))")
-            norm(dtheta) < tolerance && return theta
-            isnan(theta[1]) && break
-        end
-        theta[1] = NaN
-        return theta
-        # error("didn't converge in $i iterations")
-    end
-
-    thetas = Vector{Float64}[]
-    gen_rtic_grid!(thetas, element; npts=npts)
-    map(calc_intersection!, thetas)
-    filter!(t -> !isnan(t[1]), thetas)
-    info_output && info("thetas: $thetas")
-    secondary && filter!(t -> t[1] > 1.0e-12, thetas)
-    # error("failure finding ray trace, thetas vec is empty")
-    length(thetas) == 0 && return NaN, [NaN, NaN]
-    sort!(thetas, alg=MergeSort, lt=(a,b)->a[1]<b[1])
-    theta = thetas[1]
-    return theta[1], theta[2:end]
-end
-
-function calc_normal{S<:Union{Seg2, Seg3, NSeg}}(element::Element{S}, xi, time; deformed=true)
-    x = element["geometry"](time)
-    if deformed && haskey(element, "displacement")
-        x += element["displacement"](time)
-    end
-    Q = [0.0 1.0; -1.0 0.0]
-    dN = get_dbasis(element, xi, time)
-    n = Q*(dN*x)
-    n /= norm(n)
-    return n
-end
-
-function calc_normal{S<:Union{Quad4, NSurf}}(element::Element{S}, xi, time; deformed=true)
-    x = element["geometry"](time)
-    if deformed && haskey(element, "displacement")
-        x += element["displacement"](time)
-    end
-    dN = get_dbasis(element, xi, time)
-    J = transpose(sum([kron(dN[:,i], x[i]') for i=1:length(x)]))
-    n = cross(J[:,1], J[:,2])
-    n /= norm(n)
-    return n
-end
-
-"""
-References
-----------
-[1] http://fp.optics.arizona.edu/optomech/Fall13/Notes/6%20Mirror%20matrices.pdf
-"""
-function calc_reflection(element::Element, xi, k, time; deformed=true)
-    n = calc_normal(element, xi, time; deformed=deformed)
-    k2 = k - 2*vecdot(k, n)*n
-    return k2
-end
-
diff --git a/test/test_find_edge_intersections.jl b/test/test_find_edge_intersections.jl
deleted file mode 100644
index 97d0b06..0000000
--- a/test/test_find_edge_intersections.jl
+++ /dev/null
@@ -1,79 +0,0 @@
-# This file is a part of JuliaFEM.
-# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
-
-using JuliaFEM
-using JuliaFEM.Testing
-
-@testset "find intersection of Seg3 element" begin
-    el = Element(Seg3, [1, 2, 3])
-    update!(el, "geometry", Vector{Float64}[[0.0, 1.0], [1.0, 0.0], sqrt(2.0)/2.0*[1.0, 1.0]])
-    s = [ 1.0, 0.5]
-    d = [-1.0, 0.0]
-    t, xi = find_intersection(el, s, d, 0.0)
-    x = el("geometry", xi, 0.0)
-    @test isapprox(x, [0.8604093371313943, 0.5])
-end
-
-@testset "find intersection of 2. order NSeg element" begin
-    # this is a exact quarter of circle
-    a = 1.0
-    b = 1.0
-    el = Element(NSeg, [1, 2, 3])
-    el.properties.order = 2
-    el.properties.knots = [0.0, 0.0, 0.0, 1.0, 1.0, 1.0]
-    el.properties.weights = [1.0, 1.0, 2.0]
-    update!(el, "geometry", Vector{Float64}[[a, 0], [a, b], [0, b]])
-    s = [ 1.0, 0.5]
-    d = [-1.0, 0.0]
-    t, xi = find_intersection(el, s, d, 0.0)
-    X = el("geometry", xi, 0.0)
-    @test isapprox(X, [sqrt(3)/2, 1/2])
-end
-
-@testset "find intersection of 1. order NSurf" begin
-    # node ordering, it's not same as in Quad4
-    el = Element(NSurf, [1, 2, 3, 4])
-    el.properties.order_u = 1
-    el.properties.order_v = 1
-    el.properties.knots_u = [0.0, 0.0, 1.0, 1.0]
-    el.properties.knots_v = [0.0, 0.0, 1.0, 1.0]
-    el.properties.weights = ones(2, 2)
-    # +-- v
-    # |
-    # u
-    nodes = Vector{Float64}[[0.0,0.0,0.0], [1.0,0.0,0.0],
-                            [0.0,1.0,0.0], [1.0,1.0,0.0]]
-    update!(el, "geometry", nodes)
-    s = [0.5, 0.5,  0.5]
-    d = [0.0, 0.0, -1.0]
-    t, xi = find_intersection(el, s, d, 0.0)
-    X = el("geometry", xi, 0.0)
-    @test isapprox(X, [0.5, 0.5, 0.0])
-    k = calc_reflection(el, xi, d, 0.0)
-    @test isapprox(k, [0.0, 0.0, 1.0])
-    s = [1.5, 1.5, 0.5]
-    t, xi = find_intersection(el, s, d, 0.0)
-    @test isnan(t)
-end
-
-@testset "find intersection of 3. order NSeg element with multiple reflections" begin
-    el = Element(NSeg, [1, 2, 3, 4])
-    el.properties.order = 3
-    el.properties.knots = [0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0]
-    el.properties.weights = [1.0, 1/3, 1/3, 1.0]
-    update!(el, "geometry", Vector{Float64}[[1, 0], [1, 2], [-1, 2], [-1, 0]])
-    s1 = [-sqrt(3)/2.0, 0.0]
-    k1 = [ 0.0, 1.0]
-    t1, xi1 = find_intersection(el, s1, k1, 0.0)
-    s2 = el("geometry", xi1, 0.0)
-    @test isapprox(s2, [-sqrt(3)/2, 0.5])
-    k2 = calc_reflection(el, xi1, k1, 0.0)
-    t2, xi2 = find_intersection(el, s2, k2, 0.0; secondary=true)
-    s3 = el("geometry", xi2, 0.0)
-    @test isapprox(s3, [0.0, 1.0])
-    k3 = calc_reflection(el, xi2, k2, 0.0)
-    t3, xi3 = find_intersection(el, s3, k3, 0.0; secondary=true)
-    s4 = el("geometry", xi3, 0.0)
-    @test isapprox(s4, [sqrt(3)/2, 0.5])
-end
-