# Presentation: 770359

##        Recent Coronagraph Experimental Studies

-  TPFCWS 2006 Sep 27-28
**       ****Recent Coronagraph Experimental Studies**
**Jun Nishikawa** (NAOJ)

_**1. BABA, N. et al. (Hokkaido Univ.) **_**   ****Polarization Application**** **
**    ****MURAKAMI, SATO**
**    ****Nulling interferometer using ****Geometric (Pancharatnam) Phase** **, **
**    ****FQPM with a Liquid Crystal and *****Polarization Differential Imaging***** **
_**2. TAVROV, A. et al. (NAOJ, TUAT) **_**  ****Common-path AIC**
**   ****TAKEDA, KUROKAWA, YOKOCHI, NISHIKAWA, TAMURA, ABE**
**    *****3D Sagnac Interferometer***** using Geometric (photon spin redirection) phase**
_**3. NISHIKAWA, J. et al. (NAOJ) **_**  ****UNI-PAC **
**    ****MURAKAMI, ABE, KOTANI, TAMURA, YOKOCHI, KUROKAWA, TAVROV, TAKEDA**
**    *****Combination method, Pre-optics with NI and AO for Dynamic Range Absorption***** **
_**4. TAMURA et al. (NAOJ) **_**    ****Subaru/HiCIAO**** **
**    ****HODAPP, SUZUKI, ABE, and many people**
_**5. ENYA et al. (JAXA/ISAS) **_**    ****SPICA Coronagraph**
**    ****ABE, TANAKA, NAKAGAWA, MURAKAMI, NISHIKAWA, TAMURA, FUJITA, ITOH, KATAZA, GUYON**
_**6. FUJITA et al. (Kobe Univ.) **_**   ****Shaped Pupil****  **
**    ****ITOH**** **

## Experiment on Differential Polarization Imaging

**Experiment on Differential Polarization Imaging**

***Y. Sato, N. Murakami************* and N. Baba***
***Hokkaido Univ., *******NAOJ***

***Aim***: Extract exoplanet image from speckle noise
***Method***: Light from exoplanet is expected to be partially polarized,
-               while speckle noises are caused by unpolarized stellar light.
-               Nulling stellar coronagraph with a four-quadrant polarization
-               mask is employed.
***Result***: Exoplanet model image is detected at 5λ/D with contrast of 10-6

## Experimental Setup

**Experimental Setup**

- M

- Entrance pupil

- Lyot stop

- FQ-PoM

- P

- P

- Sharp-cut filter

- f=1000

- f=500

- f=700

- M

- CBS

- ND

- Halogen lamp
- (Planet model)

- M

- Short-pass filter

- Xenon lamp
- (Star model)

- M

- LCR

- One-wave plate ; 90°polarization
- Half-wave plate ;  0°polarization

- EM-CCD

- partially
- polarizing
- unit

## -

**=**

**0°****polarization**

**90****°****polarization**

**Difference**

**Experimental Result**

- Star model: unpolarized, **λ**; 540nm-800nm
- Planet model: partially polarized (47%), **6.4× 10****-6** @ 5.3λ/D

*Without starlight*

## TPF-C WS, 2006 Sep 28-29, Pasadena

- _Alexander Tavrov,_  M. Tamura, J. Nishikawa (NAOJ),
- Mitsuo Takeda (The Univ. of Electro-Communications),
- Takashi Kurokawa (Tokyo Univ. of Agriculture and Technology)

**TPF-C WS 2006, Sep 28-29, Pasadena**

**TPF-C WS, 2006 Sep 28-29, Pasadena**

## Input

- Achromatic Nulled output

- Bright output

- Common path Very stable

- A kind of Berry’s Geometric Phase

- A. Tavrov, R. Bohr, M. Totzeck, H. Tiziani, and M. Takeda, 2004,
-     “Achromatic nulling interferometer based on a geometric spin-redirection phase” Opt. Lett. 27, 2070.
- A. Tavrov, Y. Kobayashi, Y. Tanaka, T. Shioda, Y. Otani, and T. Kurokawa, 2005,
-     “Common-path achromatic interferometer-coronagraph: nulling of polychromatic light” Opt. Lett. 30, 2224.
- A. Tavrov, Y. Tanaka, T. Shioda, T. Kurokawa, and M. Takeda,  2005,
-     “Achromatic coronagraph based on out-of-plane common-path nulling interferometer” SPIE 5905, 824.
- A. Tavrov, Y. Otani, T. Kurokawa, and M. Takeda,  2006,
-     “Three-dimensional common-path interferometer for AIC: nulling of  polychromatic light” IAUC 200, 451.

## Rotational shearing interferometer for nulling: coronagraphy, interferometry

## Current set-up

**Set-up implements pupil re-imaging and Lyot stop**

## Auto tilt alignment

**Auto tilt alignment**

**Axial**
**position is controlled by piezo**

## Nulling analysis

**Speckle ****peak ****at ****2****.8****x10****-4**.
- (30/150 x 1.4 x10-3[attenuated bright output ]
- [He-Ne])

## Combination and Pre-Optics Studies

***Combination and Pre-Optics Studies***

- Nishikawa et al. 2005, A&A
- Combination of NI and SP
- Nishikawa & Murakami 2006, IAUC
- Combinations of  NI, AIC, FQPM, SP
- Abe et al. 2006, A&A
- Coronagraphic Pre-Optics for WFC
- Nishikawa et al. 2006, A&A revising
- Combination of UNI & PAC for Dynamic Range Absorption

## UNI

**Coronagraph**

***Second AO***
***With Two DMs***

- WFS

**Telescope**

**First AO**

***Unbalanced ***
***Nulling ***
***Interferometer***

- WFS

***Pre-optics of Coronagraph for Dynamic Range Absorption ***
***Unbalanced Nulling Interference (UNI) and ***
***Phase and Amplitude Correction (PAC) by AO system ***

- PAC

- _UNI-PAC__ __with λ/1000 optics, get λ/10000 quality_

**λ/1000 r ms**

**⇒****λ/1000**

**λ/100**

**⇒****λ/1000**

**λ/1000**** ⇒λ/100**

**λ/10000 r ms**

**⇒****λ/10000**

**Converted to Initial WF  λ/1000**

##  Description by Complex Amplitude

- UNI-PAC
-  Description by Complex Amplitude

## Effect at the Focal Plane  

**Central Star Extinction **
**~1/100**

- UNI-PAC
- Effect at the Focal Plane

- UNI-PAC Absorbs the Dynamic Range of ~1E2
- Requirements for the downstream coronagraph is relaxed.
-   DR = ~1E-8, WFE = ~lambda/1000 rms.

**Speckle Reduction **
**~1/100**

**Residual Dynamic Range**
**~1E8**

## Application possibility

- UNI-PAC

-    (a)                 (b)               (c)                (d)                                (e)
- (a) Long Baseline Interferometer
-             [LBT, VLTI, Keck Interferometer, TPF-I, Darwin, ...]
- (b) (Large) Single Telescope,  Sub-aperture Interferometer
-             [TPF-C, Subaru, VLT, Gemini, MMT, AEOS, HOP, ...]
- (c) Off-axis Single Telescope,  Overlapped Sub-Aperture Interferometer
-             [TPF-C, TPF-CP,  . . .] (VNC)
- (d) Single Telescope,  Rotation Shearing Interferometer
-             [TPF-C, TPF-CP, HOP, Subaru, VLT, Gemini, MMT, AEOS, ]  (AIC, 3D Sagnac)
- (e) Multiple application to VNC

- UNI

- -

- PAC

- UNI

- -

- PAC

- UNI

- -

- PAC

## UNI-PAC Experiments (Now)

*UNI-PAC Experiments (Now)*

**M3**

**M1**

**M2**

**M4**

**HeNe laser **

**3rd  pupil plane**

**Entrance  pupil **

**2nd pupil plane**

**WFS **

**PC **

**PC **

** ****BS**

**CCD **

## UNI-PAC Experiments (Plan)

**M3**

**M1**

**M2**

**M4**

**HeNe laser **

**PC **

**PC **

**CCD camera **

**WFS **

**1st  pupil plane**

**2nd pupil plane**

*UNI-PAC Experiments *(Plan)

## Conclusion

- _Pre-Optics with UNI & PAC  _ make it possible to reach lambda/10000 quality with lambda/1000 optics.
- It is indispensable to Terrestrial Planet Finder – Coronagraph.
- It is applicable to Ground-based Coronagraphs.

- UNI-PAC