Optical phase retarders

Transcription

1 Optical phase retarders with Liquid Crystal Polymers Pierre Piron ( FRIA phd student ) ARC : Optique-Hololab Université de Liège 1/12 Pierre Piron Optical phase retarders

2 Introduction 1. Introduction Aim of the study to design and realise optical phase retarders with Liquid Crystal Polymers (LCP) 2/12 Pierre Piron Optical phase retarders

3 Introduction 1. Introduction Aim of the study to design and realise optical phase retarders with Liquid Crystal Polymers (LCP) LCP liquid crystals connected to a polymer birefringence properties realisation of optical phase retarders 2/12 Pierre Piron Optical phase retarders

4 Realisation of the rst prototypes 2. Realisation of the rst prototypes First protoypes = simple phase retarders 3/12 Pierre Piron Optical phase retarders

5 Realisation of the rst prototypes 2. Realisation of the rst prototypes First protoypes = simple phase retarders Components for the realisation with LCP 3/12 Pierre Piron Optical phase retarders

6 Realisation of the rst prototypes 2. Realisation of the rst prototypes First protoypes = simple phase retarders Components for the realisation with LCP 1. the Linearly Photo-polymerisable Polymer (LPP) 2. the Liquid Crystal Polymer (LCP) 3/12 Pierre Piron Optical phase retarders

7 Realisation of the rst prototypes 2. Realisation of the rst prototypes First protoypes = simple phase retarders Components for the realisation with LCP 1. the Linearly Photo-polymerisable Polymer (LPP) 2. the Liquid Crystal Polymer (LCP) thickness of the layer of LCP phase retardation for ONE specic wavelength (chromatic phase retardation) φ = 2π nh λ 3/12 Pierre Piron Optical phase retarders

8 Realisation of the rst prototypes 2. Realisation of the rst prototypes 2.1. Linearly Photopolymerisable Polymer (LPP) The LPP is spincoated and baked exposed to linear polarised UV beam (325 nm) orientation of the LPP according to the electric eld 4/12 Pierre Piron Optical phase retarders

9 Realisation of the rst prototypes 2. Realisation of the rst prototypes 2.1. Linearly Photopolymerisable Polymer (LPP) The LPP is spincoated and baked exposed to linear polarised UV beam (325 nm) orientation of the LPP according to the electric eld The exposure device (actual and future) linear polarised UV beam 2 lenses collimate and expand the beam 4/12 Pierre Piron Optical phase retarders

10 Realisation of the rst prototypes 2. Realisation of the rst prototypes 2.1. Linearly Photopolymerisable Polymer (LPP) The LPP is spincoated and baked exposed to linear polarised UV beam (325 nm) orientation of the LPP according to the electric eld The exposure device (actual and future) linear polarised UV beam 2 lenses collimate and expand the beam UV quarter-wave plate + UV linear polariser select the incident polarisation rotators + translators + masks create space variant axes 4/12 Pierre Piron Optical phase retarders

11 Realisation of the rst prototypes 2. Realisation of the rst prototypes 2.2. Liquid Crystal Polymer (LCP) The LCP is spincoated on the LPP orientation of the LCP according to the LPP (according to the electric eld of the beam) baked under a nitrogen ush exposed to a UV lamp under a nitrogen ush xation of the LCP protection of the LCP to oxygen 5/12 Pierre Piron Optical phase retarders

12 Optical phase retarders Realisation of the rst prototypes 2. Realization of the rst prototypes 2.2. Liquid Crystal Polymer (LCP) I The rst prototypes incomplete exposure to the UV beam attacked by oxygen 6/12 Pierre Piron longer exposure to the UV beam no oxygen attack Optical phase retarders

13 Experimental measurings 3. Experimental measurings 3.1. The polarimetric bench (Hololab) (1) one of the laser diodes 660nm (visible) 1.55µm (infrared H-band) 2.3µm (infrared K-band) 7/12 Pierre Piron Optical phase retarders

14 Experimental measurings 3. Experimental measurings 3.1. The polarimetric bench (Hololab) (4-5) xed linear polariser achromatic quarter-wave plate create a circular polarisation (6-8) linear polarisers on nano-rotators (7) sample : the phase retarder 8/12 Pierre Piron Optical phase retarders

15 Experimental measurings 3. Experimental measurings 3.2. The measurement process start 9/12 Pierre Piron Optical phase retarders

16 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset 9/12 Pierre Piron Optical phase retarders

17 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes 9/12 Pierre Piron Optical phase retarders

18 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes crossed axes 9/12 Pierre Piron Optical phase retarders

19 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes crossed axes parallel axes 9/12 Pierre Piron Optical phase retarders

20 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes crossed axes parallel axes crossed axes 9/12 Pierre Piron Optical phase retarders

21 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes crossed axes parallel axes crossed axes parallel axes /12 Pierre Piron Optical phase retarders

22 Experimental measurings 3. Experimental measurings 3.2. The measurement process start reset parallel axes crossed axes parallel axes crossed axes parallel axes crossed axes /12 Pierre Piron Optical phase retarders

23 Experimental measurings 3. Experimental measurings 3.3. The results Interpolation formula I π 2 = sin ( I (2α) sin 4 (θ) sin 2 (Γ/2) 1 sin 2 (α) sin 2 (θ) ) sin 2 (α) sin 2 (θ) sin 2 (Γ/2) Results at 660 nm (angles in ( )) sample phase retardation phase retardation condence by calculation on the bench interval A 71,075 87,17 [86, 75 87, 58] A' 71,075 87,72 [85, 89 89, 58] B 71,075 89,06 [87, 18 90, 99] B' 71,075 88,07 [87, 59 88, 53] 10/12 Pierre Piron Optical phase retarders

24 What's next? 4. What's next? measuring at several wavelengths visible (550 nm 633 nm,...) IR (1.55µm, 2.3µm,... ) testing dierent parameters for the spincoating of the LCP (phase retardation) measuring before and after an other exposure to UV (aging) measuring every day during one week (stability) mapping of the phase retardation (homogeneity) testing dierent parameters for achromatic phase retarders 11/12 Pierre Piron Optical phase retarders

25 What's next? THE END 12/12 Pierre Piron Optical phase retarders