Optical spot array pitch compressor
An apparatus comprises a passive wavelength division multiplexing (WDM) demultiplexer (DeMUX) or a passive WDM multiplexer (MUX), an active photo diode (PD) array or an active laser diode (LD) array, and a compressing device disposed between the passive WDM DeMUX or the passive WDM MUX and the active PD array or the active LD array. The compressing device changes the optical spot pitch of the passive WDM DeMUX or the passive WDM MUX to match the pitch of the active PD array or the active LD array. The compressing device may be a single optical wedge, a first and a second optical wedges, a plurality of optical wedges, or a grating. A compression ratio can be adjusted by changing the incident angle of the incident beam to the compressing device.
1. An apparatus comprising:
one of a passive wavelength division multiplexing (WDM) demultiplexer (DeMUX) and a passive WDM multiplexer (MUX);
one of an active photo diode (PD) array and an active laser diode (LD) array;
a compressing device disposed between said one of a passive WDM DeMUX and a passive WDM MUX and said one of an active PD array and an active LD array;
wherein the compressing device changes an optical spot pitch of said one of a passive WDM DeMUX and a passive WDM MUX to match a pitch of said one of an active PD array and an active LD array; and
wherein a compression ratio can be adjusted by changing an incident angle of an incident beam to the compressing device;
wherein the compressing device is a single optical wedge; and
wherein the compression ratio can be adjusted by changing the incident angle of the incident beam to the single optical wedge according to equation:
η
=
cos
[
α
-
sin
-
1
(
sin
β
n
)
]
cos
[
sin
-
1
(
sin
β
n
)
]
×
cos
β
cos
{
sin
-
1
[
n
sin
(
α
-
sin
-
1
(
sin
β
n
)
)
]
}
,
where η is the compression ratio, β is the incident angle, α is an apex angle of the single optical wedge, and n is a refractive index of the single optical wedge.
2. The apparatus of claim 1 , wherein said one of a passive WDM DeMUX and a passive WDM MUX comprises a plurality of thin film filters (TFF).
3. The apparatus of claim 1 , wherein said one of a passive WDM DeMUX and a passive WDM MUX comprises a plurality of mirrors.
4. The apparatus of claim 1 , wherein said one of an active PD array and an active LD array comprises a plurality of lenses.
5. A method for compressing an optical spot pitch of one of a passive wavelength division multiplexing (WDM) demultiplexer (DeMUX) and a passive WDM multiplexer (MUX) to match a pitch of one of an active photo diode (PD) array and an active laser diode (LD) array comprising:
disposing a compressing device between said one of a passive WDM DeMUX and a passive WDM MUX and said one of an active PD array and an active LD array;
wherein the compressing device changes an optical spot pitch of said one of a passive WDM DeMUX and a passive WDM MUX to match a pitch of said one of an active PD array and an active LD array; and
wherein a compression ratio can be adjusted by changing an incident angle of an incident beam to the compressing device;
wherein the compressing device is a single optical wedge;
wherein the compression ratio is adjusted by changing the incident angle of the incident beam to the single optical wedge according to equation:
η
=
cos
[
α
-
sin
-
1
(
sin
β
n
)
]
cos
[
sin
-
1
(
sin
β
n
)
]
×
cos
β
cos
{
sin
-
1
[
n
sin
(
α
-
sin
-
1
(
sin
β
n
)
)
]
}
,
where η is the compression ratio, β is the incident angle, α is an apex angle of the single optical wedge, and n is a refractive index of the single optical wedge.
6. An apparatus comprising:
one of a passive wavelength division multiplexing (WDM) demultiplexer (DeMUX) and a passive WDM multiplexer (MUX);
one of an active photo diode (PD) array and an active laser diode (LD) array;
a single optical wedge disposed between said one of a passive WDM DeMUX and a passive WDM MUX and said one of an active PD array and an active LD array;
wherein the single optical wedge changes an optical spot pitch of said one of a passive WDM DeMUX and a passive WDM MUX to match a pitch of said one of an active PD array and an active LD array; and
wherein a compression ratio can be adjusted by changing an incident angle of an incident beam to the single optical wedge according to equation:
η
=
cos
[
α
-
sin
-
1
(
sin
β
n
)
]
cos
[
sin
-
1
(
sin
β
n
)
]
×
cos
β
cos
{
sin
-
1
[
n
sin
(
α
-
sin
-
1
(
sin
β
n
)
)
]
}
,
where η is the compression ratio, β is the incident angle, α is an apex angle of the single optical wedge, and n is a refractive index of the single optical wedge.
7. The apparatus of claim 6 , wherein said one of a passive WDM DeMUX and a passive WDM MUX comprises a plurality of thin film filters (TFF).
8. The apparatus of claim 6 , wherein said one of a passive WDM DeMUX and a passive WDM MUX comprises a plurality of mirrors.
9. The apparatus of claim 6 , wherein said one of an active PD array and an active LD array comprises a plurality of lenses.