Various Types of Surface Profiles

Holographic surfaces are created by engraving, embossing, or patterning micro- and nanoscale structures that interact with light to produce unique optical effects. The surface profile determines how light is diffracted, reflected, or manipulated to create the holographic image. Below are the most common holographic surface profiles used in security, branding, and optical applications.

1. Diffractive Grating-Based Profiles

These profiles use finely spaced grooves to split and diffract light into different colours and patterns.

A. Linear Gratings

Structure: Parallel lines etched at a specific pitch (e.g., 800–1,200 lines per mm).

Effect: Creates a rainbow or colour shift effect when viewed from different angles.

Applications: Security foils, holographic labels, optical diffusers.

B. Crossed or 2D Gratings

Structure: Two perpendicular grating patterns.

Effect: Produces a multi-directional diffraction effect.

Applications: Anti-counterfeiting features, optical elements.

C. Blazed Gratings (Sawtooth Profile)

Structure: Asymmetric grating with a sawtooth-like pattern.

Effect: Directs light in a preferred direction, improving efficiency.

Applications: Laser optics, high-precision diffractive elements.

2. Micro-Relief Structures

These profiles use varying depths and shapes to scatter and diffract light differently.

A. Sinusoidal Relief Profile

Structure: Smooth, wave-like undulations.

Effect: Produces soft, gradient-like holographic effects.

Applications: Decorative packaging, security foils.

B. Stair-Step (Binary) Relief Profile

Structure: Discrete step-like levels in height.

Effect: Used to approximate complex diffractive wavefronts.

Applications: Diffractive optical elements (DOEs), security holograms.

3. Geometric and Pattern-Based Profiles

These profiles combine structured geometric elements to create unique optical effects.

A. Micro-Lens Arrays

Structure: Thousands of tiny lens-like shapes embossed on the surface.

Effect: Creates 3D depth, magnification, and dynamic movement.

Applications: High-security authentication, decorative holography.

B. Metasurface Holograms

Structure: Uses nanostructured elements (plasmonic/metamaterials) to control light.

Effect: Produces ultra-thin, high-resolution holograms with unique light interactions.

Applications: Advanced security foils, optical sensors, display technologies.

C. Dot-Matrix Holograms

Structure: Arranged microdots form an image through diffraction.

Effect: High-resolution and dynamic effects visible from different angles.

Applications: Banknotes, ID cards, brand protection.

4. Randomized and Hybrid Profiles

These profiles combine multiple diffraction effects to enhance security.

A. Stochastic (Randomized) Surface Profile

Structure: Non-repetitive, irregular surface structures.

Effect: Extremely difficult to duplicate, providing strong anti-counterfeiting.

Applications: High-security holograms for government documents.

B. Hybrid Gratings & Microstructures

Structure: Combination of gratings, micro-lens arrays, and relief patterns.

Effect: Creates complex, multi-layered optical security effects.

Applications: Advanced authentication features, high-end branding.

In short,

Linear & blazed gratings → Great for simple colour-shifting effects.

Micro-lens arrays & meta surfaces → Used for high-resolution 3D security features.

Randomized profiles & hybrid structures → Provide advanced anti-counterfeiting solutions.