Structural, Thermal & Optical Performance (STOP) Engine

The STOP Optics Optimizer is an interactive web platform designed to evaluate and optimize circular and annular mirror assemblies. It couples thermo-elastic mechanical deformations directly to optical wavefront quality, allowing optical designers and mechanical engineers to iterate quickly without local software installations.

The platform provides two primary modes of access depending on your organization:

Selecting a substrate defines the mechanical stiffness and thermal sensitivity of the mirror. Select a preset from the dropdown menu, or choose Custom Substrate to specify proprietary values:

Input the primary physical dimensions in millimeters. The interface provides real-time validation to verify that dimensions remain within realistic manufacturing aspect ratios:

Stage 1 models the optical substrate resting horizontally under 1.00g gravity during interferometric optical testing, polishing, or mount adhesive curing. The physical reaction boundary conditions automatically adapt based on your chosen Mirror Structural Architecture:

🔵 5.1 Option A: Solid Flat Optics — Continuous Annular Cushion Support Option A

For solid blanks, the rear face rests on a compliant elastomeric or knife-edge continuous circular annular band. This balances inner sag against outer cantilever overhang roll-off.

Figure 1A: Kinematic annular support showing mean ring radius a_mfg, contact band width ΔR, and optical clear aperture CA.

Support Ring Radius (a_mfg) [mm]:

Mean radial location of the annular ring. For minimum gravity sag on a solid disk, the optimal theoretical balance occurs near a_mfg ≈ 0.681 × R.

Support Ring Bandwidth (ΔR) [mm]:

Contact radial width of the annular cushion. Uniform reaction pressure is computed as q_contact = M·g / [2π a_mfg ΔR].

Dual-Surface RMS Tracking: Because both the front optical clear aperture and the back mounting plane are continuous surfaces, Stage 1 evaluates deflection profiles, Peak-to-Valley (PV) sag, and Zernike modal expansions for both surfaces.

🔶 5.2 Option B: Hexagonal Honeycomb Mirror — Stage 1 3-Point Symmetric Kinematic Joint Support Option B

For lightweighted mirrors with open-back pocket cavities, a continuous annular cushion cannot be used because it would span unsupported thin pocket floors, inducing severe localized bending ("oil-canning"). Instead, the mirror features a true regular hexagonal honeycomb rib architecture (derived from centered hexagonal numbers N(n) = 1 + 3n(n−1) for rings k = n−1). The mirror is supported kinematically on 3 green kinematic columns with hollow circular planar pads located strictly at 120° rotational symmetry directly beneath hexagonal rib-intersection joint vertices, extending up into 3 blind counterbore holes on the back face. No outer rim support is required during Stage 1.

Fig 1: Stage 1 Kinematic 3-Column Support Setup (Option B: Honeycomb) — (Left) Top Plan View: Continuous regular hexagonal honeycomb core, purely imaginary central hub guide circle (passes through joint supports without interrupting hex pockets), 3 hollow circular support pads (ΔR_pad, r_hole), and perimeter Blade Patch #0 at Top (90°); (Right) Front Sectional Elevation View: 3 green kinematic support columns extending UP into 3 blind counterbore holes in the substrate back face (depth d_blind stopping safely above floor t_floor without penetrating the front optical face). Reaction pressure distributes across the 3 hollow circular areas: σ_pad = M·g / [3π(r_pad² − r_hole²)].

Figure 1B-1: True Symmetrical Hexagonal Honeycomb back-face geometry (n=3, 19 regular hex pockets, stiffener ribs, and outer bounding circle).

Figure 1B-2: Honeycomb progression across Pocket Base Parameter n ∈ {1, 2, 3, 4} → N ∈ {1, 7, 19, 37} pockets with exact outer touching bounding circles.

Mathematical Hexagonal Honeycomb & Pad Reaction Formulas:

Total Hexagons: N(n) = 1 + 3n(n−1)

Hex Side / Arm: s = R / √N

Cavity Pocket Arm: s_pocket = max(0.1, s − w_rib/√3)

Hole Radius: r_hole = r_pad − ΔR_pad

Hollow Pad Area: A_pad = π(r_pad² − r_hole²)

Pad Stress: σ_pad = M·g / (3 A_pad)

Honeycomb Base Parameter (n):

Governs pocket order sequence (n=1..5 → 1, 7, 19, 37, 61 pockets). Configured with nominal value and bounds [n_min, n_max] so the multi-tier optimizer selects the best structural mass/sag trade-off.

Imaginary Hub Pitch (r_hub) [mm]:

Purely imaginary reference guide circle passing through joint supports; does not cut away honeycomb core cells. Pockets remain continuous across the substrate.

Pad Outer Radius & ΔR_pad [mm]:

Outer radius r_pad and wall width ΔR_pad defining hollow circular pads with blind hole radius r_hole = r_pad − ΔR_pad. Reaction pressure distributes over the 3 hollow areas: σ_pad = M·g / [3π(r_pad² − r_hole²)].

Symmetric Triad Selection:

Choice of canonical 120° joint vertex triplet on the hexagonal grid where the 3 planar pads are placed. Auto (-1) selects the Airy-optimal minimum deflection node triad.

Rib Wall Thickness (w_rib) [mm]:

Structural rib thickness providing bearing stiffness directly under the support pads and transferring transverse shear loads across pocket walls.

Uniform Pocket Floor (t_floor) [mm]:

Uniform faceplate thickness across all cells forming the polished front optical reflective boundary. Back blind holes stop safely above floor t_floor, keeping the front optical plane solid.

⚠️ Crucial Engineering Principle: Back Surface RMS is NOT Evaluated for Honeycomb Mirrors

Because the back face of a lightweighted honeycomb mirror contains open pocket cavities and thin rib walls, calculating an optical surface figure RMS, PV sag, or Zernike modal expansion on the back face is physically meaningless. The solver explicitly sets back surface optical metrics to N/A (Pocketed Back Face) and concentrates all wavefront optimization strictly on the continuous front optical faceplate (z = −h/2).

Stage 2 models the optic installed inside its operational housing, kinematically retained by three mechanical mounting blades bonded to adhesive patches spaced at 120° around the outer cylindrical rim. The coordinate frame positions Blade Patch 0 at the Top (12 o'clock, θ = 90°), Blade Patch 1 at θ = 210° (lower-left), and Blade Patch 2 at θ = 330° (lower-right), with in-plane gravity pointing downward opposing elevation tilt:

Figure 2: Operational assembly kinematics: (Left) Planar Mount with Blade Patch 0 at Top (90°) and downward in-plane gravity, (Center) Input-Time 3D Spatial Attitude & Kinematics Telemetry showing Elevation 60.0° [Zenith / Facing Up] with optical axis pointing upward and 1g downward gravity, and (Right) Cylindrical Rim Bond with axial offset z_shift and notch stress concentration.

The platform provides two selectable Zernike representations to ensure direct compatibility with your downstream optical design or testing software:

The platform processes simulations sequentially through an automated cloud execution queue. Here is how your job progresses from submission to deliverable retrieval:

Upon completion, download the complete package as STOP_Optics_Deliverable.zip containing:

Tax invoices are issued in compliance with statutory Central Goods and Services Tax (GST) provisions:

• Service Accounting Code: Designated under SAC 998145 ("Research and development originals in other fields n.e.c.").
• Standard Referencing: Deliverables and invoices explicitly reference published international standards (ISO 24157, ISO 14999-2) for audit compliance.
• Institutional Purchase Orders (PO): Organizations purchasing through procurement channels will have their designated PO reference numbers printed directly on the final invoice.

Users and organizations can manage and reference past runs via the user portal: